Navy Aegis Ballistic Missile Defense (BMD) Program: Background and Issues for Congress

Changes from August 28, 2023 to December 20, 2023

This page shows textual changes in the document between the two versions indicated in the dates above. Textual matter removed in the later version is indicated with ~~red strikethrough~~ and textual matter added in the later version is indicated with blue.

Navy Aegis Ballistic Missile Defense (BMD)
~~August 28~~December 20, 2023 , 2023
Program: Background and Issues for Congress
Ronald O'Rourke
The Aegis ballistic missile defense (BMD) program, which is carried out by the Missile Defense The Aegis ballistic missile defense (BMD) program, which is carried out by the Missile Defense
Specialist in Naval Affairs Specialist in Naval Affairs
Agency (MDA) and the Navy, gives Navy Aegis cruisers and destroyers a capability for Agency (MDA) and the Navy, gives Navy Aegis cruisers and destroyers a capability for

conducting BMD operations. BMD-capable Aegis ships operate in European waters to defend conducting BMD operations. BMD-capable Aegis ships operate in European waters to defend
Europe from potential ballistic missile attacks from countries such as Iran, and in in the Western Europe from potential ballistic missile attacks from countries such as Iran, and in in the Western

Pacific and the Persian Gulf to provide regional defense against potential ballistic missile attacks Pacific and the Persian Gulf to provide regional defense against potential ballistic missile attacks
from countries such as North Korea and Iran. The number of BMD-capable Aegis ships has been growing over time. MDA’s from countries such as North Korea and Iran. The number of BMD-capable Aegis ships has been growing over time. MDA’s
FY2024 budget submission states that “by the end of FY 2024, there will be 53 total BMD capable [Aegis] ships requiring FY2024 budget submission states that “by the end of FY 2024, there will be 53 total BMD capable [Aegis] ships requiring
maintenance support.” maintenance support.”
The Aegis BMD program is funded mostly through MDA’s budget. The Navy’s budget provides additional funding for The Aegis BMD program is funded mostly through MDA’s budget. The Navy’s budget provides additional funding for
BMD-related efforts. MDA’s proposed FY2024 budget requests a total of $1,747.2 million (i.e., about $1.7 billion) in BMD-related efforts. MDA’s proposed FY2024 budget requests a total of $1,747.2 million (i.e., about $1.7 billion) in
procurement and research and development funding for Aegis BMD efforts, including funding for two Aegis Ashore sites in procurement and research and development funding for Aegis BMD efforts, including funding for two Aegis Ashore sites in
Poland and Romania. MDA’s budget also includes operations and maintenance (O&M) and military construction (MilCon) Poland and Romania. MDA’s budget also includes operations and maintenance (O&M) and military construction (MilCon)
funding for the Aegis BMD program. funding for the Aegis BMD program.
Issues for Congress regarding the Aegis BMD program include the following: Issues for Congress regarding the Aegis BMD program include the following:
• whether to approve, reject, or modify MDA’s annual procurement and research and development funding • whether to approve, reject, or modify MDA’s annual procurement and research and development funding
requests for the program; requests for the program;
• the adequacy of MDA’s cost estimating and its reporting of costs; • the adequacy of MDA’s cost estimating and its reporting of costs;
• what role the Aegis BMD program should play in defending the U.S. homeland against attack from • what role the Aegis BMD program should play in defending the U.S. homeland against attack from
ICBMs; ICBMs;
• required versus available numbers of BMD-capable Aegis ships; • required versus available numbers of BMD-capable Aegis ships;
• the burden that BMD operations may be placing on the Navy’s fleet of Aegis ships, and whether there are • the burden that BMD operations may be placing on the Navy’s fleet of Aegis ships, and whether there are
alternative ways to perform BMD missions now performed by U.S. Navy Aegis ships, such as establishing alternative ways to perform BMD missions now performed by U.S. Navy Aegis ships, such as establishing
additional Aegis Ashore sites; additional Aegis Ashore sites;
• allied burden sharing—how allied contributions to regional BMD capabilities and operations compare to • allied burden sharing—how allied contributions to regional BMD capabilities and operations compare to
U.S. naval contributions to overseas regional BMD capabilities and operations; U.S. naval contributions to overseas regional BMD capabilities and operations;
• whether to convert the Aegis test facility in Hawaii into an operational land-based Aegis BMD site; • whether to convert the Aegis test facility in Hawaii into an operational land-based Aegis BMD site;
• the potential for ship-based lasers to contribute in coming years to Navy terminal-phase BMD operations • the potential for ship-based lasers to contribute in coming years to Navy terminal-phase BMD operations
and the impact this might eventually have on required numbers of ship-based BMD interceptor missiles; and the impact this might eventually have on required numbers of ship-based BMD interceptor missiles;
and and
• deliveries, testing, and technical risk in the Aegis BMD program. • deliveries, testing, and technical risk in the Aegis BMD program.

Congressional Research Service Congressional Research Service

Navy Aegis Ballistic Missile Defense (BMD) Program

Introduction
This report provides background information and issues for Congress on the Aegis ballistic This report provides background information and issues for Congress on the Aegis ballistic
missile defense (BMD) program, a program carried out by the Missile Defense Agency (MDA) missile defense (BMD) program, a program carried out by the Missile Defense Agency (MDA)
and the Navy that gives Navy Aegis cruisers and destroyers a capability for conducting BMD and the Navy that gives Navy Aegis cruisers and destroyers a capability for conducting BMD
operations. The issue for Congress is whether to approve, reject, or modify Department of operations. The issue for Congress is whether to approve, reject, or modify Department of
Defense (DOD) acquisition strategies and proposed funding levels for the Aegis BMD program. Defense (DOD) acquisition strategies and proposed funding levels for the Aegis BMD program.
Congress’s decisions on the Aegis BMD program could significantly affect U.S. BMD Congress’s decisions on the Aegis BMD program could significantly affect U.S. BMD
capabilities and funding requirements, and the BMD-related industrial base. capabilities and funding requirements, and the BMD-related industrial base.
Background
Aegis Ships
All but three of the Navy’s cruisers and destroyers are called Aegis ships because they are All but three of the Navy’s cruisers and destroyers are called Aegis ships because they are
equipped with the Aegis ship combat system—an integrated collection of sensors, computers, equipped with the Aegis ship combat system—an integrated collection of sensors, computers,
software, displays, weapon launchers, and weapons named for the mythological shield that software, displays, weapon launchers, and weapons named for the mythological shield that
defended Zeus. (The exceptions are the Navy’s three Zumwalt [DDG-1000] class destroyers, defended Zeus. (The exceptions are the Navy’s three Zumwalt [DDG-1000] class destroyers,
which are discussed below.) The Aegis system was originally developed in the 1970s for which are discussed below.) The Aegis system was originally developed in the 1970s for
defending ships against aircraft, anti-ship cruise missiles (ASCMs), surface threats, and defending ships against aircraft, anti-ship cruise missiles (ASCMs), surface threats, and
subsurface threats. The system was first deployed by the Navy in 1983, and it has been updated subsurface threats. The system was first deployed by the Navy in 1983, and it has been updated
many times since. The Navy’s Aegis ships include Ticonderoga (CG-47) class cruisers and many times since. The Navy’s Aegis ships include Ticonderoga (CG-47) class cruisers and
Arleigh Burke (DDG-51) class destroyers. Arleigh Burke (DDG-51) class destroyers.
Ticonderoga (CG-47) Class Aegis Cruisers
A total of 27 CG-47s (CGs 47 through 73) were procured for the Navy between FY1978 and A total of 27 CG-47s (CGs 47 through 73) were procured for the Navy between FY1978 and
FY1988; the ships entered service between 1983 and 1994. The first five ships in the class (CGs FY1988; the ships entered service between 1983 and 1994. The first five ships in the class (CGs
47 through 51), which were built to an earlier technical standard in certain respects, were judged 47 through 51), which were built to an earlier technical standard in certain respects, were judged
by the Navy to be too expensive to modernize and were removed from service in 2004-2005, by the Navy to be too expensive to modernize and were removed from service in 2004-2005,
leaving 22 ships in operation (CGs 52 through 73). Retirements of these 22 ships began in leaving 22 ships in operation (CGs 52 through 73). Retirements of these 22 ships began in
FY2022. The Navy’s FY2024 budget submission projects that 13 will remain in service at the end FY2022. The Navy’s FY2024 budget submission projects that 13 will remain in service at the end
of FY2023, and proposes that these 13 ships be retired in FY2024 (five ships), FY2025 (three of FY2023, and proposes that these 13 ships be retired in FY2024 (five ships), FY2025 (three
ships), FY2026 (three ships), and FY2027 (two ships). ships), FY2026 (three ships), and FY2027 (two ships).
Arleigh Burke (DDG-51) Class Aegis Destroyers
The Navy began procuring DDG-51s in FY1985, and a total of 92 have been procured through The Navy began procuring DDG-51s in FY1985, and a total of 92 have been procured through
FY2023. The first DDG-51 entered service in 1991, and a total of 74 have been delivered as of FY2023. The first DDG-51 entered service in 1991, and a total of 74 have been delivered as of
August 2023. Under the Navy’s FY2024 budget submission, retirements of older DG-51s are to August 2023. Under the Navy’s FY2024 budget submission, retirements of older DG-51s are to
begin in FY2028. begin in FY2028.
The DDG-51 design has been updated multiple times over the years. The first 28 DDG-51s are The DDG-51 design has been updated multiple times over the years. The first 28 DDG-51s are
known as Flight I/II DDG-51s. The next 34, known as Flight IIA DDG-51s, incorporate some known as Flight I/II DDG-51s. The next 34, known as Flight IIA DDG-51s, incorporate some
significant design changes, including the addition of a helicopter hangar. The version currently significant design changes, including the addition of a helicopter hangar. The version currently
being procured, called the Flight III DDG-51 design, incorporates another significant change—a being procured, called the Flight III DDG-51 design, incorporates another significant change—a
new radar, called the SPY 6 radar (and prior to that, the Air and Missile Defense Radar, or new radar, called the SPY 6 radar (and prior to that, the Air and Missile Defense Radar, or
AMDR), that is more capable than the SPY-1 radar installed on CG-47s and earlier DDG-51s. AMDR), that is more capable than the SPY-1 radar installed on CG-47s and earlier DDG-51s.
No DDG-51s were procured in FY2006-FY2009. The Navy during this period instead procured No DDG-51s were procured in FY2006-FY2009. The Navy during this period instead procured
the three above-mentioned Zumwalt (DDG-1000) class destroyers. The DDG-1000 design does the three above-mentioned Zumwalt (DDG-1000) class destroyers. The DDG-1000 design does
Congressional Research Service Congressional Research Service

1 1

link to page 7 link to page 7 link to page 7 link to page 7 Navy Aegis Ballistic Missile Defense (BMD) Program

not use the Aegis system and does not include a capability for conducting BMD operations. Navy not use the Aegis system and does not include a capability for conducting BMD operations. Navy
plans do not call for modifying the three DDG-1000s to make them BMD-capable.1 plans do not call for modifying the three DDG-1000s to make them BMD-capable.1
Aegis Ships in Allied Navies
Sales of the Aegis system to allied countries began in the late 1980s. Allied countries that now Sales of the Aegis system to allied countries began in the late 1980s. Allied countries that now
operate, are building, or are planning to build Aegis-equipped ships include Japan, South Korea, operate, are building, or are planning to build Aegis-equipped ships include Japan, South Korea,
Australia, Spain, and Norway.2 Japan’s Aegis-equipped ships are BMD-capable. The Aegis-Australia, Spain, and Norway.2 Japan’s Aegis-equipped ships are BMD-capable. The Aegis-
equipped ships operated by South Korea, Australia, Spain, and Norway are currently not BMD-equipped ships operated by South Korea, Australia, Spain, and Norway are currently not BMD-
capable. capable.
Aegis BMD System3
Aegis ships are given a capability for conducting BMD operations by incorporating changes to Aegis ships are given a capability for conducting BMD operations by incorporating changes to
the Aegis system’s computers and software, and by arming the ships with BMD interceptor the Aegis system’s computers and software, and by arming the ships with BMD interceptor
missiles. Older Aegis ships can be modified to become BMD-capable ships, and DDG-51s missiles. Older Aegis ships can be modified to become BMD-capable ships, and DDG-51s
procured in FY2010 and subsequent years have been built from the start with a BMD capability. procured in FY2010 and subsequent years have been built from the start with a BMD capability.
Versions and Capabilities of Aegis BMD System
Overview
The Aegis BMD system exists in multiple variants whose ascending numerical designations The Aegis BMD system exists in multiple variants whose ascending numerical designations
indicate ascending levels of capability. As part of MDA’s FY2022 budget submission, the indicate ascending levels of capability. As part of MDA’s FY2022 budget submission, the
designations of Aegis BMD system variants were changed and consolidated to 4.X, 5.X, and 6.X, designations of Aegis BMD system variants were changed and consolidated to 4.X, 5.X, and 6.X,
with the X indicating multiple subvariants. (The 4.X variant, for example, includes the 4.1 and with the X indicating multiple subvariants. (The 4.X variant, for example, includes the 4.1 and
4.2 subvariants.4) 4.2 subvariants.4)
BMD system variants correlate with certain versions (i.e., baselines, or BLs) of the overall Aegis BMD system variants correlate with certain versions (i.e., baselines, or BLs) of the overall Aegis
system, which have their own numbering system. The more recent BMD variants, in addition to system, which have their own numbering system. The more recent BMD variants, in addition to
being able to address more challenging BMD scenarios, give BMD-equipped ships a capability to being able to address more challenging BMD scenarios, give BMD-equipped ships a capability to
simultaneously perform both BMD operations against ballistic missiles and anti-air warfare simultaneously perform both BMD operations against ballistic missiles and anti-air warfare
(AAW) operations (aka air-defense operations) against aircraft and anti-ship cruise missiles. (AAW) operations (aka air-defense operations) against aircraft and anti-ship cruise missiles.
Figure 1 provides a 2019 Government Accountability Office (GAO) summary of the capabilities provides a 2019 Government Accountability Office (GAO) summary of the capabilities
of the more recent BMD variants and their correlation to Aegis system baselines as of 2019. of the more recent BMD variants and their correlation to Aegis system baselines as of 2019.
BecausBecause Figure 1 was prepared in 2019, it uses the older designations for Aegis BMD system was prepared in 2019, it uses the older designations for Aegis BMD system
variants, rather than the new designations that were introduced as part of the MDA’s FY2022 variants, rather than the new designations that were introduced as part of the MDA’s FY2022
budget submission. budget submission.
The Aegis BMD system was originally designed primarily to intercept theater-range ballistic The Aegis BMD system was originally designed primarily to intercept theater-range ballistic
missiles, meaning short-, medium-, and intermediate-range ballistic missiles (SRBMs, MRBMs, missiles, meaning short-, medium-, and intermediate-range ballistic missiles (SRBMs, MRBMs,
and IRBMs, respectively). In addition to its capability for intercepting theater-range ballistic and IRBMs, respectively). In addition to its capability for intercepting theater-range ballistic

1 For more on the DDG-51 and DDG-1000 programs, see CRS Report RL32109, 1 For more on the DDG-51 and DDG-1000 programs, see CRS Report RL32109, Navy DDG-51 and DDG-1000
Destroyer Programs: Background and Issues for Congress, by Ronald O'Rourke. , by Ronald O'Rourke.
2 The Norwegian ships are somewhat smaller than the other Aegis ships, and consequently carry a reduced-size version 2 The Norwegian ships are somewhat smaller than the other Aegis ships, and consequently carry a reduced-size version
of the Aegis system that includes a smaller, less-powerful version of the SPY-1 radar. of the Aegis system that includes a smaller, less-powerful version of the SPY-1 radar.
3 Unless stated otherwise, information in this section is taken from MDA briefings on the Aegis BMD program given to 3 Unless stated otherwise, information in this section is taken from MDA briefings on the Aegis BMD program given to
CRS and CBO analysts on the MDA’s FY2023 and prior-year budget submissions. CRS and CBO analysts on the MDA’s FY2023 and prior-year budget submissions.
4 The 4.X variant is the new designation for the variants previously designated 3.6.X, 4.0.X, 4.1, and 4.2. The 5.X 4 The 4.X variant is the new designation for the variants previously designated 3.6.X, 4.0.X, 4.1, and 4.2. The 5.X
variant is the new designation for the variants previously designated 5.0CU (with the CU standing for Capability variant is the new designation for the variants previously designated 5.0CU (with the CU standing for Capability
Upgrade) and 5.1. The 6.X variant is the new designation for the variant previously designated 6.0. Upgrade) and 5.1. The 6.X variant is the new designation for the variant previously designated 6.0.
Congressional Research Service Congressional Research Service

2 2

Navy Aegis Ballistic Missile Defense (BMD) Program

missiles, detection and tracking data collected by the Aegis BMD system’s radar might be passed missiles, detection and tracking data collected by the Aegis BMD system’s radar might be passed
to other U.S. BMD systems that are designed to intercept intercontinental ballistic missiles to other U.S. BMD systems that are designed to intercept intercontinental ballistic missiles
(ICBMs), which might support intercepts of ICBMs that are conducted by those other U.S. BMD (ICBMs), which might support intercepts of ICBMs that are conducted by those other U.S. BMD
systems. systems.
Figure 1. GAO Summary of Capabilities of Aegis BMD System Variants

Source: Government Accountability Office, Government Accountability Office, Missile Defense[:] Delivery Delays Provide Opportunity for Increased
Testing to Better Understand Capability, GAO-19-387, June 2019, Table 5 on p. 31. , GAO-19-387, June 2019, Table 5 on p. 31.
Aegis BMD Interceptor Missiles
The BMD interceptor missiles used by Aegis ships are the Standard5 Missile-3 (SM-3) and the The BMD interceptor missiles used by Aegis ships are the Standard5 Missile-3 (SM-3) and the
SM-6. SM-6.
SM-3 Midcourse Interceptor
The SM-3 is designed to intercept ballistic missiles above the atmosphere (i.e., exo-atmospheric The SM-3 is designed to intercept ballistic missiles above the atmosphere (i.e., exo-atmospheric
intercept), in the midcourse phase of an enemy ballistic missile’s flight. It is equipped with a “hit-intercept), in the midcourse phase of an enemy ballistic missile’s flight. It is equipped with a “hit-
to-kill” warhead, called a kinetic vehicle, that is designed to destroy a ballistic missile’s warhead to-kill” warhead, called a kinetic vehicle, that is designed to destroy a ballistic missile’s warhead

5 The Standard Missile is so named because it was originally developed, decades ago, as a surface-to-air (i.e., air 5 The Standard Missile is so named because it was originally developed, decades ago, as a surface-to-air (i.e., air
defense) missile to serve as the common (i.e., standard) successor to the Navy’s then-existing collection of Talos, defense) missile to serve as the common (i.e., standard) successor to the Navy’s then-existing collection of Talos,
Terrier, and Tartar air defense missiles, which were sometimes referred to collectively as the 3-T missiles. Terrier, and Tartar air defense missiles, which were sometimes referred to collectively as the 3-T missiles.
Congressional Research Service Congressional Research Service

3 3

Navy Aegis Ballistic Missile Defense (BMD) Program

by colliding with it. The current versions of the SM-3 missile include the SM-3 Block IA, the by colliding with it. The current versions of the SM-3 missile include the SM-3 Block IA, the
SM-3 Block IB, and the SM-3 Block IIA.6 SM-3 Block IB, and the SM-3 Block IIA.6
Compared to the Block IA version, the Block IB version has an improved (two-color) target Compared to the Block IA version, the Block IB version has an improved (two-color) target
seeker, an advanced signal processor, and an improved divert/attitude control system for adjusting seeker, an advanced signal processor, and an improved divert/attitude control system for adjusting
its course. Compared to the Block IA and 1B versions, which have a 21-inch-diameter booster its course. Compared to the Block IA and 1B versions, which have a 21-inch-diameter booster
stage at the bottom but are 13.5 inches in diameter along the remainder of their lengths, the Block stage at the bottom but are 13.5 inches in diameter along the remainder of their lengths, the Block
IIA version has a 21-inch diameter along its entire length. The increase in diameter to a uniform IIA version has a 21-inch diameter along its entire length. The increase in diameter to a uniform
21 inches provides more room for rocket fuel, permitting the Block IIA version to have a burnout 21 inches provides more room for rocket fuel, permitting the Block IIA version to have a burnout
velocity (a maximum velocity, reached at the time the propulsion stack burns out) that is greater velocity (a maximum velocity, reached at the time the propulsion stack burns out) that is greater
than that of the Block IA and IB versions, as well as a larger-diameter kinetic warhead. The than that of the Block IA and IB versions, as well as a larger-diameter kinetic warhead. The
United States and Japan cooperated in developing certain technologies for the Block IIA version, United States and Japan cooperated in developing certain technologies for the Block IIA version,
with Japan funding a significant share of the effort.7 with Japan funding a significant share of the effort.7
A March 31, 2020, press report stated A March 31, 2020, press report stated
Raytheon and the Missile Defense Agency are exploring options to extend the range of the Raytheon and the Missile Defense Agency are exploring options to extend the range of the
Standard Missile-3 Block IB—pushing the ballistic missile interceptor to dramatically Standard Missile-3 Block IB—pushing the ballistic missile interceptor to dramatically
expand a defended area by allowing the weapon to communicate with off-board radars—a expand a defended area by allowing the weapon to communicate with off-board radars—a
move that would require enhancing one of the Aegis ballistic missile defense system’s move that would require enhancing one of the Aegis ballistic missile defense system’s
newest features: Engage-on-Remote…. newest features: Engage-on-Remote….
MDA Director Vice Adm. Jon Hill told Congress earlier this month that the new Engage- MDA Director Vice Adm. Jon Hill told Congress earlier this month that the new Engage-
on-Remote capability provides “a seven-fold increase in missile defense coverage when on-Remote capability provides “a seven-fold increase in missile defense coverage when
compared to an autonomous Aegis platform.”8 compared to an autonomous Aegis platform.”8
SM-6 Terminal Interceptor (Overview)
The SM-2 Block IV was MDA’s and the Navy’s initial sea-based terminal-phase (SBT) BMD The SM-2 Block IV was MDA’s and the Navy’s initial sea-based terminal-phase (SBT) BMD
interceptor. It was designed to intercept ballistic missiles inside the atmosphere (i.e., endo-interceptor. It was designed to intercept ballistic missiles inside the atmosphere (i.e., endo-
atmospheric intercept), during the terminal phase of an enemy ballistic missile’s flight. It was atmospheric intercept), during the terminal phase of an enemy ballistic missile’s flight. It was
equipped with a blast fragmentation warhead. A limited number of these missiles were produced equipped with a blast fragmentation warhead. A limited number of these missiles were produced
years ago.9 The SM-2 Block IV has now been replaced by the SM-6. years ago.9 The SM-2 Block IV has now been replaced by the SM-6.
The SM-6 is MDA’s and the Navy’s more capable next-generation SBT BMD interceptor. It is The SM-6 is MDA’s and the Navy’s more capable next-generation SBT BMD interceptor. It is
based on the SM-6 air defense missile (the Navy’s successor to the SM-2 air defense missile). based on the SM-6 air defense missile (the Navy’s successor to the SM-2 air defense missile).
The SM-6 is a dual-capability missile that can be used for either air defense (i.e., countering The SM-6 is a dual-capability missile that can be used for either air defense (i.e., countering
aircraft and ASCMs) or ballistic missile defense. A July 23, 2018, press report states the aircraft and ASCMs) or ballistic missile defense. A July 23, 2018, press report states the
following: following:
The Defense Department has launched a prototype project that aims to dramatically The Defense Department has launched a prototype project that aims to dramatically
increase the speed and range of the Navy’s Standard Missile-6 by adding a larger rocket increase the speed and range of the Navy’s Standard Missile-6 by adding a larger rocket

6 MDA and Navy plans at one point called for the SM-3 Block IIA to be succeeded by a still-more-capable interceptor 6 MDA and Navy plans at one point called for the SM-3 Block IIA to be succeeded by a still-more-capable interceptor
called the SM-3 Block IIB. The effort to develop that missile, however, was ended years ago, and MDA at the time was called the SM-3 Block IIB. The effort to develop that missile, however, was ended years ago, and MDA at the time was
reportedly not pursuing any follow-on capabilities to the SM-3 Block IIA. (See, for example, Justin Doubleday, reportedly not pursuing any follow-on capabilities to the SM-3 Block IIA. (See, for example, Justin Doubleday,
“Missile Defense Agency Not Pursuing Follow-On to SM-3 Block IIA Interceptor,” “Missile Defense Agency Not Pursuing Follow-On to SM-3 Block IIA Interceptor,” Inside the Navy, October 24, , October 24,
2016.) 2016.)
7 The cooperative research effort was carried out under a U.S.-Japan memorandum of agreement signed in 1999. The 7 The cooperative research effort was carried out under a U.S.-Japan memorandum of agreement signed in 1999. The
effort focused on risk reduction for four parts of the missile: the sensor, an advanced kinetic warhead, the second-stage effort focused on risk reduction for four parts of the missile: the sensor, an advanced kinetic warhead, the second-stage
propulsion, and a lightweight nose cone. propulsion, and a lightweight nose cone.
8 Jason Sherman, “After MDA Demonstrates 7x Increase in Defended Area, Raytheon Pitching EOR for Older SM-3s,” 8 Jason Sherman, “After MDA Demonstrates 7x Increase in Defended Area, Raytheon Pitching EOR for Older SM-3s,”
Inside Defense, March 31, 2020. , March 31, 2020.
9 The inventory of SM-2 Block IVs was created by modifying SM-2s that were originally built to intercept aircraft and 9 The inventory of SM-2 Block IVs was created by modifying SM-2s that were originally built to intercept aircraft and
ASCMs. A total of 75 SM-2 Block IVs were modified, and at least 3 were used in BMD flight tests through February ASCMs. A total of 75 SM-2 Block IVs were modified, and at least 3 were used in BMD flight tests through February
2012. 2012.
Congressional Research Service Congressional Research Service

4 4

Navy Aegis Ballistic Missile Defense (BMD) Program

motor to the ship-launched weapon, a move that aims to improve both the offensive and motor to the ship-launched weapon, a move that aims to improve both the offensive and
defensive reach of the Raytheon-built system. defensive reach of the Raytheon-built system.
On Jan. 17 [2018], the Navy approved plans to develop a Dual Thrust Rocket Motor with On Jan. 17 [2018], the Navy approved plans to develop a Dual Thrust Rocket Motor with
a 21-inch diameter for the SM-6, which is currently fielded with a 13.5-inch propulsion a 21-inch diameter for the SM-6, which is currently fielded with a 13.5-inch propulsion
package. The new rocket motor would sit atop the current 21-inch booster, producing a package. The new rocket motor would sit atop the current 21-inch booster, producing a
new variant of the missile: the SM-6 Block IB.10 new variant of the missile: the SM-6 Block IB.10
SM-6 Terminal Interceptor (Hypersonic Threat Intercept Capability)
MDA and the Navy are developing a capability for the SM-6 to intercept hypersonic missiles. MDA and the Navy are developing a capability for the SM-6 to intercept hypersonic missiles.
MDA testified in May 2022 MDA testified in May 2022
We are investing in defensive capabilities to counter regional hypersonic missile threats by We are investing in defensive capabilities to counter regional hypersonic missile threats by
upgrading sensors and C2BMC [Command and Control, Battle Management and upgrading sensors and C2BMC [Command and Control, Battle Management and
Communications] for early warning, identification, and tracking of regional and strategic Communications] for early warning, identification, and tracking of regional and strategic
hypersonic threats from space (e.g., HBTSS [Hypersonic and Ballistic Tracking Space hypersonic threats from space (e.g., HBTSS [Hypersonic and Ballistic Tracking Space
Sensor]). We also are leveraging existing systems where possible (including proven Sensor]). We also are leveraging existing systems where possible (including proven
engage-on-remote and launch-on-remote capabilities) and pursuing a Glide Phase Intercept engage-on-remote and launch-on-remote capabilities) and pursuing a Glide Phase Intercept
(GPI) demonstration. We are working closely with the Navy to develop, field, and upgrade (GPI) demonstration. We are working closely with the Navy to develop, field, and upgrade
the SBT [sea-based terminal defense] capability to counter regional maneuvering and the SBT [sea-based terminal defense] capability to counter regional maneuvering and
hypersonic threats in the terminal phase of flight. The SBT program already provides an hypersonic threats in the terminal phase of flight. The SBT program already provides an
initial terminal defensive capability to counter hypersonic threats, and additional initial terminal defensive capability to counter hypersonic threats, and additional
improvements are scheduled for 2024. Today, the SM-6 missile is the only weapon in the improvements are scheduled for 2024. Today, the SM-6 missile is the only weapon in the
country’s arsenal capable of engaging highly-maneuverable hypersonic threats. In FY country’s arsenal capable of engaging highly-maneuverable hypersonic threats. In FY
2023, Aegis SBT will demonstrate a simulated engagement against a hypersonic target 2023, Aegis SBT will demonstrate a simulated engagement against a hypersonic target
(FTX-40) and in FY 2024 will demonstrate a salvo engagement firing two SM-6 Block IA (FTX-40) and in FY 2024 will demonstrate a salvo engagement firing two SM-6 Block IA
Upgraded guided missiles against a Hypersonic Glide Vehicle target (FTM-43). Upgraded guided missiles against a Hypersonic Glide Vehicle target (FTM-43).
Complementing this terminal capability, in FY 2023, MDA will continue to develop and Complementing this terminal capability, in FY 2023, MDA will continue to develop and
plan a GPI demonstration and leverage the Aegis Weapon System to provide the U.S. plan a GPI demonstration and leverage the Aegis Weapon System to provide the U.S.
Warfighter increasingly capable regional defensive capabilities.11 Warfighter increasingly capable regional defensive capabilities.11
MDA testified in May 2023 MDA testified in May 2023
MDA plans to conduct a Tracking Exercise, Flight Test Other (FTX)-23, with two Aegis MDA plans to conduct a Tracking Exercise, Flight Test Other (FTX)-23, with two Aegis
ships to perform target scene data collection of an MRBM with countermeasures. We will ships to perform target scene data collection of an MRBM with countermeasures. We will
also demonstrate Aegis SBT with a salvo engagement in Flight Test Aegis Weapon System also demonstrate Aegis SBT with a salvo engagement in Flight Test Aegis Weapon System
(FTM)-32, firing two (salvo) SM-6 Dual II software upgrade guided missiles against a (FTM)-32, firing two (salvo) SM-6 Dual II software upgrade guided missiles against a
MRBM. In FTX-40 we will fire a simulated SM-6 missile against a hypersonic glide MRBM. In FTX-40 we will fire a simulated SM-6 missile against a hypersonic glide
vehicle…. vehicle….
We also are developing a layered defense capability against regional hypersonic threats We also are developing a layered defense capability against regional hypersonic threats
and have initiated a development program for a Glide Phase Interceptor, leveraging and have initiated a development program for a Glide Phase Interceptor, leveraging
existing systems where possible, including proven engage-on-remote and launch-on-existing systems where possible, including proven engage-on-remote and launch-on-
remote capabilities. We are focusing on the proven Aegis Weapon System to provide the remote capabilities. We are focusing on the proven Aegis Weapon System to provide the
depth-of-fire needed for a layered defense against hypersonic threats. In FY 2024, MDA depth-of-fire needed for a layered defense against hypersonic threats. In FY 2024, MDA
will continue to develop and mature the GPI capability and leverage the Aegis Weapon will continue to develop and mature the GPI capability and leverage the Aegis Weapon
System. Today, MDA already provides the Navy an initial terminal defense capability. We System. Today, MDA already provides the Navy an initial terminal defense capability. We
also are working closely with the Navy to develop, field, and upgrade SBT defenses to also are working closely with the Navy to develop, field, and upgrade SBT defenses to
counter more advanced maneuvering and hypersonic threats. We anticipate delivering counter more advanced maneuvering and hypersonic threats. We anticipate delivering
these Increment 3 capabilities in 2025. In FY 2024, Aegis SBT will demonstrate an these Increment 3 capabilities in 2025. In FY 2024, Aegis SBT will demonstrate an

10 Jason Sherman, “Navy Looking to Increase Range, Speed of SM-6 with Larger Rocket Motor,” 10 Jason Sherman, “Navy Looking to Increase Range, Speed of SM-6 with Larger Rocket Motor,” Inside the Navy, July , July
23, 2018. 23, 2018.
11 [Statement of] Vice Admiral Jon A. Hill, USN, Director, Missile Defense Agency, Before the Senate Armed Services 11 [Statement of] Vice Admiral Jon A. Hill, USN, Director, Missile Defense Agency, Before the Senate Armed Services
Committee, Strategic Forces Subcommittee, May 18, 2022, p. 10. See also Jason Sherman, “DOD Delays by Two Committee, Strategic Forces Subcommittee, May 18, 2022, p. 10. See also Jason Sherman, “DOD Delays by Two
Years Maiden Intercept Attempt of Hypersonic Glide Vehicle Target.” Years Maiden Intercept Attempt of Hypersonic Glide Vehicle Target.” Inside Defense, May 17, 2023. , May 17, 2023.
Congressional Research Service Congressional Research Service

5 5

Navy Aegis Ballistic Missile Defense (BMD) Program

engagement against an advanced target in the terminal phase (FTM-32) and a simulated engagement against an advanced target in the terminal phase (FTM-32) and a simulated
engagement against a hypersonic glide vehicle (FTX-40). In FY 2025, SBT Increment 3 engagement against a hypersonic glide vehicle (FTX-40). In FY 2025, SBT Increment 3
will demonstrate an engagement against a hypersonic glide vehicle firing an SM-6 Block will demonstrate an engagement against a hypersonic glide vehicle firing an SM-6 Block
IAU missile (FTM-43).12 IAU missile (FTM-43).12
Numbers of BMD-Capable Aegis Ships
The number of BMD-capable Aegis ships has been growing over time. MDA’s FY2024 budget The number of BMD-capable Aegis ships has been growing over time. MDA’s FY2024 budget
submission states that “by the end of FY 2024, there will be 53 total BMD capable [Aegis] ships submission states that “by the end of FY 2024, there will be 53 total BMD capable [Aegis] ships
requiring maintenance support.”13 requiring maintenance support.”13
BMD-Capable Aegis Destroyers Forward-Homeported in Spain
On October 5, 2011, the United States, Spain, and NATO jointly announced that four BMD-On October 5, 2011, the United States, Spain, and NATO jointly announced that four BMD-
capable U.S. Navy Aegis destroyers were to be forward-homeported (i.e., based) at the naval base capable U.S. Navy Aegis destroyers were to be forward-homeported (i.e., based) at the naval base
at Rota, Spain.14 The initial set of four ships was transferred to Rota in FY2014 and FY2015.15 at Rota, Spain.14 The initial set of four ships was transferred to Rota in FY2014 and FY2015.15
They were replaced at Rota by a new set of four BMD-capable U.S. Navy Aegis destroyers in They were replaced at Rota by a new set of four BMD-capable U.S. Navy Aegis destroyers in
2020-2022.16 2020-2022.16
Navy officials said the four Rota-based ships can provide a level of level of presence in the Navy officials said the four Rota-based ships can provide a level of level of presence in the
Mediterranean for performing BMD patrols and other missions equivalent to what could be Mediterranean for performing BMD patrols and other missions equivalent to what could be
provided by about 10 BMD-capable Aegis ships that are homeported on the U.S. east coast, thus provided by about 10 BMD-capable Aegis ships that are homeported on the U.S. east coast, thus
effectively releasing about six U.S. Navy BMD-capable Aegis ships for performing BMD patrols effectively releasing about six U.S. Navy BMD-capable Aegis ships for performing BMD patrols
or other missions elsewhere. or other missions elsewhere.
In February and March 2020, DOD officials testified that DOD was considering forward-In February and March 2020, DOD officials testified that DOD was considering forward-
homeporting an additional two BMD-capable Aegis destroyers at Rota, which would make for a homeporting an additional two BMD-capable Aegis destroyers at Rota, which would make for a
total of six destroyers at the site.17 Navy officials testified in 2020 that they supported the idea.18 total of six destroyers at the site.17 Navy officials testified in 2020 that they supported the idea.18
On June 28, 2022, the Biden Administration announced that two additional Aegis destroyers On June 28, 2022, the Biden Administration announced that two additional Aegis destroyers

12 [Statement of] Vice Admiral Jon A. Hill, USN, Director, Missile Defense Agency, Before the House Armed Services 12 [Statement of] Vice Admiral Jon A. Hill, USN, Director, Missile Defense Agency, Before the House Armed Services
Committee Strategic Forces Subcommittee, May 9, 2023, pp. 8, 10-11. Committee Strategic Forces Subcommittee, May 9, 2023, pp. 8, 10-11.
13 Missile Defense Agency, 13 Missile Defense Agency, Fiscal Year 2024 Budget Estimates, Missile Defense Agency, March 2023, p. 11. (This is , March 2023, p. 11. (This is
the FY2024 budget justification book for MDA’s portion of the Operation and Maintenance, Defense-Wide the FY2024 budget justification book for MDA’s portion of the Operation and Maintenance, Defense-Wide
appropriation account.) appropriation account.)
14 “Announcement on missile defence cooperation by NATO Secretary General Anders Fogh Rasmussen, the Prime 14 “Announcement on missile defence cooperation by NATO Secretary General Anders Fogh Rasmussen, the Prime
Minister of Spain, Jose Luis Rodriguez Zapatero and US Defense Secretary Leon Panetta,” October 5, 2011, accessed Minister of Spain, Jose Luis Rodriguez Zapatero and US Defense Secretary Leon Panetta,” October 5, 2011, accessed
May 18, 2022, at http://www.nato.int/cps/en/SID-107ADE55-FF83A6B8/natolive/opinions_78838.htm. See also May 18, 2022, at http://www.nato.int/cps/en/SID-107ADE55-FF83A6B8/natolive/opinions_78838.htm. See also
“SECDEF Announces Stationing of Aegis Ships at Rota, Spain,” accessed May 18, 2022, at https://web.archive.org/“SECDEF Announces Stationing of Aegis Ships at Rota, Spain,” accessed May 18, 2022, at https://web.archive.org/
web/20120117065346/http:/www.navy.mil/search/display.asp?story_id=63109. web/20120117065346/http:/www.navy.mil/search/display.asp?story_id=63109.
Rota is on the southwestern Atlantic coast of Spain, a few miles northwest of Cadiz, and about 65 miles northwest of Rota is on the southwestern Atlantic coast of Spain, a few miles northwest of Cadiz, and about 65 miles northwest of
the Strait of Gibraltar leading into the Mediterranean. U.S. Navy ships have been homeported at Rota at various points the Strait of Gibraltar leading into the Mediterranean. U.S. Navy ships have been homeported at Rota at various points
in the past, most recently (prior to the current arrangement) in 1979. (Source: Sam Fellman, “U.S. To Base Anti-in the past, most recently (prior to the current arrangement) in 1979. (Source: Sam Fellman, “U.S. To Base Anti-
Missile Ships in Spain,” Defense News, October 10, 2011: 76.) Missile Ships in Spain,” Defense News, October 10, 2011: 76.)
15 The four ships were the destroyers 15 The four ships were the destroyers Ross (DDG-71) and (DDG-71) and Donald Cook (DDG-75), which moved to Rota in FY2014, (DDG-75), which moved to Rota in FY2014,
and the destroyers and the destroyers Carney (DDG-64) and (DDG-64) and Porter (DDG-78), which moved to Rota in FY2015. (DDG-78), which moved to Rota in FY2015.
16 See, for example, Mallory Shelbourne, “USS Arleigh Burke Arrives in Spain, USS Donald Cook Will Head to 16 See, for example, Mallory Shelbourne, “USS Arleigh Burke Arrives in Spain, USS Donald Cook Will Head to
Mayport,” Mayport,” USNI News, April 12, 2021. , April 12, 2021.
17 See, for example, Paul McCleary, “EUCOM Calls For Two More Ships For Spanish Port,” 17 See, for example, Paul McCleary, “EUCOM Calls For Two More Ships For Spanish Port,” Breaking Defense, ,
February 25, 2020; David B. Larter, “Push to Base Six US Navy Destroyers in Spain Could Be Gaining Steam,” February 25, 2020; David B. Larter, “Push to Base Six US Navy Destroyers in Spain Could Be Gaining Steam,”
Defense News, March 3, 2020. , March 3, 2020.
18 See, for example, David B. Larter, “The US Navy’s Top Officer Declares Support for Basing 6 Destroyers in Spain,” 18 See, for example, David B. Larter, “The US Navy’s Top Officer Declares Support for Basing 6 Destroyers in Spain,”
Defense News, March 5, 2020. See also John Vandiver, “Rota to Gain Two US Destroyers by Middle of the Decade, , March 5, 2020. See also John Vandiver, “Rota to Gain Two US Destroyers by Middle of the Decade,
EUCOM Chief Says,” EUCOM Chief Says,” Stars and Stripes, April 15, 2021. es, April 15, 2021.
Congressional Research Service Congressional Research Service

6 6

Navy Aegis Ballistic Missile Defense (BMD) Program

would be homeported at Rota.19 The Navy confirmed that the two additional Aegis destroyers are would be homeported at Rota.19 The Navy confirmed that the two additional Aegis destroyers are
to be BMD-capable.20 An October 24, 2022, press report stated that “the U.S. and Spain will soon to be BMD-capable.20 An October 24, 2022, press report stated that “the U.S. and Spain will soon
launch negotiations on a new defense pact for an expanded naval presence in Spain,” including launch negotiations on a new defense pact for an expanded naval presence in Spain,” including
the two additional BMD-capable Aegis destroyers. The report stated that “while an official the two additional BMD-capable Aegis destroyers. The report stated that “while an official
timeline for the ships’ arrival in Spain hasn’t been set, U.S. military commanders have put 2025 timeline for the ships’ arrival in Spain hasn’t been set, U.S. military commanders have put 2025
or 2026 as target years.”21 On May 8, 2023, Spain and the United States reportedly signed the or 2026 as target years.”21 On May 8, 2023, Spain and the United States reportedly signed the
new agreement.22 new agreement.22
Aegis Ashore Sites
Two Navy-Operated Sites in Romania and Poland
The land-based version of the Aegis BMD system is called Aegis Ashore. There are two Aegis The land-based version of the Aegis BMD system is called Aegis Ashore. There are two Aegis
Ashore sites in Europe—one in Romania, and one in Poland. The sites are intended to help Ashore sites in Europe—one in Romania, and one in Poland. The sites are intended to help
defend Europe against ballistic missile threats from countries such as Iran. Each Aegis Ashore site defend Europe against ballistic missile threats from countries such as Iran. Each Aegis Ashore site
includes a structure housing an Aegis system that is similar to the deckhouse on an Aegis ship, includes a structure housing an Aegis system that is similar to the deckhouse on an Aegis ship,
and 24 SM-3 missiles launched from a relocatable Vertical Launch System (VLS) based on the and 24 SM-3 missiles launched from a relocatable Vertical Launch System (VLS) based on the
VLS that is installed in Navy Aegis ships.23 VLS that is installed in Navy Aegis ships.23
The plan to establish the two Aegis Ashore sites in Romania and Poland was announced in 2009, The plan to establish the two Aegis Ashore sites in Romania and Poland was announced in 2009,
as part of a plan for providing regional BMD defense in Europe called the European Phased as part of a plan for providing regional BMD defense in Europe called the European Phased
Adaptive Approach (EPAA). The Aegis Ashore site in Romania achieved operational certification Adaptive Approach (EPAA). The Aegis Ashore site in Romania achieved operational certification
in May 2016.24 The site in Poland began construction in May 201625 and was initially scheduled in May 2016.24 The site in Poland began construction in May 201625 and was initially scheduled
to be completed in 2018. Its completion, however, to be completed in 2018. Its completion, however, ~~has been delayed~~was delayed for years by construction contractor by construction contractor
performance issues.26 performance issues.26 ~~An August 23, 2023, press report stated that MDA is aiming to turn the~~At a December 7, 2023, hearing on regional missile defense assets before the Strategic Forces subcommittee of the House Armed Services Committee, Rear Admiral Douglas L. Williams, the acting director of MDA, testified that

19 White House, “Press Gaggle by Press Secretary Karine Jean-Pierre and National Security Advisor Jake Sullivan En 19 White House, “Press Gaggle by Press Secretary Karine Jean-Pierre and National Security Advisor Jake Sullivan En
Route Madrid, Spain,” June 28, 2022. See also Mallory Shelbourne, “Biden Administration Basing Two More Route Madrid, Spain,” June 28, 2022. See also Mallory Shelbourne, “Biden Administration Basing Two More
Destroyers in Rota, Spain,” Destroyers in Rota, Spain,” USNI News, June 28 (updated June 29), 2022; Justin Katz, “‘A Powerful Signal:’ What It , June 28 (updated June 29), 2022; Justin Katz, “‘A Powerful Signal:’ What It
Means to Send Two More DDGs to Spain,” Means to Send Two More DDGs to Spain,” Breaking Defense, July 1, 2022; Aaron Mehta, “US Increasing Troop , July 1, 2022; Aaron Mehta, “US Increasing Troop
Presence in Europe, While New NATO Strategy Eyes China,” Presence in Europe, While New NATO Strategy Eyes China,” Breaking Defense, June 29, 2022; Geoff Ziezulewicz , June 29, 2022; Geoff Ziezulewicz
(Associated Press), “Two More Navy Destroyers Will Be Homeported in Rota, Spain,” (Associated Press), “Two More Navy Destroyers Will Be Homeported in Rota, Spain,” Navy Times, June 29, 2022. , June 29, 2022.
20 Source: Navy Office of Legislative Affairs email to CRS, July 1, 2022. 20 Source: Navy Office of Legislative Affairs email to CRS, July 1, 2022.
21 John Vandiver, “Talks on Addition of 2 Navy Destroyers at Base in Spain Expected to Start Soon,” 21 John Vandiver, “Talks on Addition of 2 Navy Destroyers at Base in Spain Expected to Start Soon,” Stars and
Stripes, October 24, 2022. , October 24, 2022.
22 Heather Mongilio, “U.S., Spain Agree to Host Two More Warships in Rota,” 22 Heather Mongilio, “U.S., Spain Agree to Host Two More Warships in Rota,” USNI News, May 9, 2023. , May 9, 2023.
23 For additional discussion of the Aegis Ashore sites, see Edward Lundquist, “Aegis Ashore Adapts Sea-Based Missile 23 For additional discussion of the Aegis Ashore sites, see Edward Lundquist, “Aegis Ashore Adapts Sea-Based Missile
Defense System to Protect Europe,” Defense System to Protect Europe,” National Defense, September 2016. , September 2016.
24 See, for example, Amy Forsythe, “U.S. Navy Aegis Ashore Base in Romania Hosts NATO Country Ambassadors,” 24 See, for example, Amy Forsythe, “U.S. Navy Aegis Ashore Base in Romania Hosts NATO Country Ambassadors,”
Defense Visual Information Distribution Service (DVIDS), November 19, 2019; “Aegis Ashore,” Missile Defense Defense Visual Information Distribution Service (DVIDS), November 19, 2019; “Aegis Ashore,” Missile Defense
Advocacy Alliance, accessed May 18, 2022, at https://missiledefenseadvocacy.org/defense-systems/aegis-ashore/; US Advocacy Alliance, accessed May 18, 2022, at https://missiledefenseadvocacy.org/defense-systems/aegis-ashore/; US
Naval Forces Europe-Africa, “Aegis Ashore Missile Defense System (AAMDS)-Romania Operationally Certified,” Naval Forces Europe-Africa, “Aegis Ashore Missile Defense System (AAMDS)-Romania Operationally Certified,”
Defense-Aerospace.com, May 12, 2016. Defense-Aerospace.com, May 12, 2016.
25 See, for example, “Aegis Ashore,” Missile Defense Advocacy Alliance, accessed May 18, 2022, at 25 See, for example, “Aegis Ashore,” Missile Defense Advocacy Alliance, accessed May 18, 2022, at
https://missiledefenseadvocacy.org/defense-systems/aegis-ashore/. https://missiledefenseadvocacy.org/defense-systems/aegis-ashore/.
26 Source: [Statement of] Vice Admiral Jon A. Hill, USN, Director, Missile Defense Agency, Before the Senate Armed 26 Source: [Statement of] Vice Admiral Jon A. Hill, USN, Director, Missile Defense Agency, Before the Senate Armed
Services Committee, Strategic Forces Subcommittee, May 18, 2022, p. 8. Earlier reporting said construction of the Services Committee, Strategic Forces Subcommittee, May 18, 2022, p. 8. Earlier reporting said construction of the
Poland site would be complete by the end of 2022. See, for example, Rich Abott, “Aegis Ashore Poland Set To Be Poland site would be complete by the end of 2022. See, for example, Rich Abott, “Aegis Ashore Poland Set To Be
Operational By End Of 2022,” Operational By End Of 2022,” Defense Daily, November 22, 2021; Jen Judson, “Construction of Aegis Ashore in , November 22, 2021; Jen Judson, “Construction of Aegis Ashore in
Poland Nearing Completion,” Poland Nearing Completion,” Defense News, March 9, 2022. See also Daniel Wasserbly, “US MDA Plans to Turn On , March 9, 2022. See also Daniel Wasserbly, “US MDA Plans to Turn On
Polish Aegis Ashore Site in June, After Years of Delay,” Polish Aegis Ashore Site in June, After Years of Delay,” Jane’s Defence Weekly, May 24, 2022. , May 24, 2022.
Congressional Research Service Congressional Research Service

7 7

Navy Aegis Ballistic Missile Defense (BMD) Program

~~Polish site over to the Navy by the end of 2023, and to have the system be fully operational by the~~
~~spring of 2024~~Aegis Ashore Poland, located in Redzikowo, was added to the Operational Capability Baseline in September 2023 with upgrades over the original design and state-of-the-art Integrated Electronic Security System. Aegis Ashore Poland was delivered to the U.S. Navy on October 1, 2023 for operational use and maintenance. The Navy will formally accept Aegis Ashore Poland into their inventory on December 15, 2023. This will complete EPAA Phase 3, originally established in 2009. The Navy will install additional upgrades at Aegis Ashore Poland through May 2024, after which it will transfer to NATO in July 2024 for command and control of Aegis Ashore Poland in the defense of NATO European states against ballistic missile threats originating outside the Euro-Atlantic area.27 .27
Navy Interest in Divesting Aegis Ashore Sites It Operates
On January 11, 2021, the Chief of Naval Operations (CNO), Admiral Michael Gilday, released a On January 11, 2021, the Chief of Naval Operations (CNO), Admiral Michael Gilday, released a
guidance document for the Navy entitled guidance document for the Navy entitled CNO NavPlan (with NavPlan being short for navigation (with NavPlan being short for navigation
plan) that states plan) that states
To remain ahead of our competitors, we will divest ourselves of legacy capabilities that no To remain ahead of our competitors, we will divest ourselves of legacy capabilities that no
longer bring sufficient lethality to the fight. This includes divestment of experimental longer bring sufficient lethality to the fight. This includes divestment of experimental
Littoral Combat Ship hulls, legacy Cruisers, and older Dock Landing Ships. It also includes Littoral Combat Ship hulls, legacy Cruisers, and older Dock Landing Ships. It also includes
divesting non-core Navy missions like Aegis-ashore. Transferring shore-based Ballistic divesting non-core Navy missions like Aegis-ashore. Transferring shore-based Ballistic
Missile Defense sites to ground forces enables Sailors to focus on their core missions at Missile Defense sites to ground forces enables Sailors to focus on their core missions at
sea and frees up resources to increase our lethality.28 sea and frees up resources to increase our lethality.28
A January 12, 2021, press report states A January 12, 2021, press report states
The chief of naval operation’s new call to focus on sea control and power projection could The chief of naval operation’s new call to focus on sea control and power projection could
lead the service to shed other non-core missions the Navy conducts today, such as manning lead the service to shed other non-core missions the Navy conducts today, such as manning
Aegis Ashore missile defense sites. Aegis Ashore missile defense sites.
The biggest problem is, no one else has agreed to take over that mission yet…. The biggest problem is, no one else has agreed to take over that mission yet….
… no one else operates Aegis systems today, and no one has yet agreed to take over Aegis … no one else operates Aegis systems today, and no one has yet agreed to take over Aegis
Ashore, Rear Adm. Paul Schlise, the director of surface warfare on the CNO’s staff Ashore, Rear Adm. Paul Schlise, the director of surface warfare on the CNO’s staff
(OPNAV N96), said today during a panel presentation at the Surface Navy Association’s (OPNAV N96), said today during a panel presentation at the Surface Navy Association’s
annual symposium. annual symposium.
“It’s been an ongoing discussion in the building here. Right now we’ve got the Aegis “It’s been an ongoing discussion in the building here. Right now we’ve got the Aegis
Ashore sites in Europe, and there’s discussions about potentially more sites in other places. Ashore sites in Europe, and there’s discussions about potentially more sites in other places.
The general discussion has been, this is not a core Navy mission. Sailors really belong at The general discussion has been, this is not a core Navy mission. Sailors really belong at
sea serving in ships. And we’ve got a good number of highly qualified folks serving in sea serving in ships. And we’ve got a good number of highly qualified folks serving in
those sites, they’re going a great job,” he said. those sites, they’re going a great job,” he said.
“But I think what the CNO teed up is, is this a core Navy mission? I don’t think it is. And “But I think what the CNO teed up is, is this a core Navy mission? I don’t think it is. And
so there’s been some discussion with the Army. The Army, of course, has some missile so there’s been some discussion with the Army. The Army, of course, has some missile
defense capability and of course great soldiers that serve in those roles. But they don’t have defense capability and of course great soldiers that serve in those roles. But they don’t have
any experience with that [Aegis Combat System], the systems that have been installed or any experience with that [Aegis Combat System], the systems that have been installed or
are in progress in Romania and Poland. So that’s been a running discussion.” are in progress in Romania and Poland. So that’s been a running discussion.”
Schlise said the discussion is taking place at the Office of the Secretary of Defense level. Schlise said the discussion is taking place at the Office of the Secretary of Defense level.
Without any final decisions, though, the Navy could not shed Aegis Ashore spending in its Without any final decisions, though, the Navy could not shed Aegis Ashore spending in its
~~most recent budgeting work, the Fiscal Year 2022 request that will come out after the Biden~~
~~administration comes in and can review it.~~
~~“For the purposes of this past budget cycle, it was just kind of tabled. So we’ll have to see~~
~~where that discussion goes. As always, here in the building, it’s about money. So if that~~
~~transition were to be considered and approved for moving forward, to transition it to~~
~~another service, ‘who’s going to pay’ will of course be part of the discussion,” Schlise~~
~~said.29~~

~~27 Rich Abott, “Poland Aegis Ashore Site To Turn Over To Navy This Year, Operational In 2024,” Defense Daily,~~
~~August 23, 2023.~~
~~28 U.S. Navy, Chief of Naval Operations, CNO NavPlan, January 2021, p. 10. See also Richard R. Burgess, “CNO:~~
~~Divest Aegis Ashore Sites to Ground Forces,” Seapower, January 11, 2021.~~
~~29 Megan Eckstein, “Navy Wants to Shed Aegis Ashore Mission, But Army Still Hasn’t Agreed to Take It,”~~ ~~USNI~~
~~News, January 12, 2021.~~
~~Congressional Research Service~~

8

~~Navy Aegis Ballistic Missile Defense (BMD) Program~~

~~Japan Planned and Later Canceled Two Sites~~
~~Prior to June 2020, Japan had planned to procure and operate two Aegis Ashore systems that~~
~~reportedly were to have been located at Ground Self-Defense Force (GSDF) facilities in Akita~~
~~Prefecture in eastern Japan and Yamaguchi Prefecture in western Japan, and were to have been~~
~~operated mainly by the GSDF (i.e., Japan’s army).30 The~~ 27 [Statement of] Rear Admiral Douglas L. Williams, USN, Director (Acting), Missile Defense Agency, Before the House Armed Services Committee, Strategic Forces Subcommittee, December 7, 2023, [on] Demand for Theater Missile Defense Assets, pp. 3-4. See also Jason Sherman, “After ‘Grossly Unacceptable Delay,’ Aegis Ashore Poland Set for Navy Inventory, Maintenance,” Inside Defense, December 7, 2023; Joseph Trevithick, “Aegis Missile Defense Site In Poland To Finally Go Operational (Updated),” The Drive, December 7, 2023. 28 U.S. Navy, Chief of Naval Operations, CNO NavPlan, January 2021, p. 10. See also Richard R. Burgess, “CNO: Divest Aegis Ashore Sites to Ground Forces,” Seapower, January 11, 2021. Congressional Research Service 8 Navy Aegis Ballistic Missile Defense (BMD) Program most recent budgeting work, the Fiscal Year 2022 request that will come out after the Biden administration comes in and can review it. “For the purposes of this past budget cycle, it was just kind of tabled. So we’ll have to see where that discussion goes. As always, here in the building, it’s about money. So if that transition were to be considered and approved for moving forward, to transition it to another service, ‘who’s going to pay’ will of course be part of the discussion,” Schlise said.29 Japan Planned and Later Canceled Two Sites Prior to June 2020, Japan had planned to procure and operate two Aegis Ashore systems.30 The two systems reportedly were to have two systems reportedly were to have
been equipped with a new Lockheed-made radar called the Long Range Discrimination Radar been equipped with a new Lockheed-made radar called the Long Range Discrimination Radar
(LRDR) rather than the Raytheon-made SPY-6 AMDR that is being installed on U.S. Navy Flight (LRDR) rather than the Raytheon-made SPY-6 AMDR that is being installed on U.S. Navy Flight
III DDG-51s, and reportedly were to go into operation by 2023.31 On June 15, 2020, however, III DDG-51s, and reportedly were to go into operation by 2023.31 On June 15, 2020, however,
Japan announced that it had suspended implementation of its Aegis Ashore initiative due to cost Japan announced that it had suspended implementation of its Aegis Ashore initiative due to cost
growth and technical concerns.32 On June 25, 2020, Japan confirmed that it had canceled the plan growth and technical concerns.32 On June 25, 2020, Japan confirmed that it had canceled the plan
for deploying the two Aegis Ashore sites. for deploying the two Aegis Ashore sites.
Rather than building the two Aegis Ashore systems, Japan now plans to instead build two Rather than building the two Aegis Ashore systems, Japan now plans to instead build two
additional BMD-additional BMD-capable Aegis ships.33 A June 23, 2023, press report stated that once the two additional BMD-capable Aegis ships go into service, Japan’s other eight BMD-capable destroyers will revert to anti-air-warfare (AAW) operations.34 Use of Aegis BMD Elements in Guam Missile Defense Architecture After studying various possible BMD system architectures for Guam, DOD proposed a system combining elements of the Aegis BMD system with elements of Army BMD systems. A March 30, 2022, press report states The Missile Defense Agency’s initial plan for the architecture to protect Guam turns to proven systems to help the agency meet a 2026 fielding deadline, according Vice Adm. Jon Hill, the agency’s director. The defense of Guam from potential ballistic, cruise and hypersonic missile attacks has become a priority for the MDA, which is seeking $539 million in fiscal 2023 to continue 29 Megan Eckstein, “Navy Wants to Shed Aegis Ashore Mission, But Army Still Hasn’t Agreed to Take It,” USNI News, January 12, 2021. ~~capable Aegis ships that are to be dedicated to BMD operations. A September 6,~~
~~2022, press report states~~
~~Japan’s Ministry of Defence is proposing to build a pair of ballistic missile defense ships—~~
~~the [sic] among largest warships in the Japanese inventory since World War II—~~
~~government officials said last week....~~
~~The two ships would be built instead of the land-based Aegis Ashore installations that the~~
~~Japanese Self-Defence Force backed away from in 2020 based on risks of missile debris~~
~~falling to the ground, USNI News reported at the time....~~
~~The two Aegis destroyers are expected to have a displacement of around 20,000 tons with~~
~~a length of 690 feet and a beam of around 130 feet, making them one of the largest and~~
~~heaviest ship that the JMSDF will operate. In comparison the Izumo class helicopter~~
~~destroyers have a displacement 19,800 tons (27,000 tons with a full load) with a length of~~
~~800 feet and a beam of 124 feet while Japan’s largest destroyers are the Maya class~~
~~destroyers, which have a displacement of 8200 tons and a beam of 22.2 meters.~~
~~The ships are to have a crew of 110 personnel with personnel accommodations being~~
~~enhanced to enable long deployments on station around Japan. The Ministry of Defense is~~
~~likely pushing for the first ship to be commissioned in 2027, with the second in 2028, USNI~~
~~News understands....~~
~~[Japan Defense Minister Yasukazu] Hamada said that the two destroyers would be large~~
~~enough to enable operations that would be carried out in rough weather and enhanced crew~~
~~quarters to allow the ships to conduct longer deployments. The Japanese defense chief also~~
~~said that the ability to intercept hypersonic glide weapons would also be included in the~~
~~ships’ capabilities.~~

30 Yomiuri Shimbun, “Akita, Yamaguchi to Get Aegis Ashore/GSDF Involvement Expected to Strengthen Missile 30 Yomiuri Shimbun, “Akita, Yamaguchi to Get Aegis Ashore/GSDF Involvement Expected to Strengthen Missile
Defense,” Defense,” The Japan News, November 11, 2017. See also Kyodo, “Japan Mulling News Missile Interceptor , November 11, 2017. See also Kyodo, “Japan Mulling News Missile Interceptor
Deployment to Guard Against North Korea,” Deployment to Guard Against North Korea,” South China Morning Post, November 11, 2017. , November 11, 2017.
31 Anthony Capaccio, “Japan in Talks With U.S. on Buying Aegis Missile Defense,” 31 Anthony Capaccio, “Japan in Talks With U.S. on Buying Aegis Missile Defense,” Bloomberg, November 7, 2017. , November 7, 2017.
32 See, for example, Rich Abott, “Japan Suspends Aegis Ashore Due To Technical And Cost Concerns,” 32 See, for example, Rich Abott, “Japan Suspends Aegis Ashore Due To Technical And Cost Concerns,” Defense Daily, ,
June 15, 2020; Sam LaGrone, “Japan Backing Away From Aegis Ashore,” June 15, 2020; Sam LaGrone, “Japan Backing Away From Aegis Ashore,” USNI News, June 15, 2020; Mari , June 15, 2020; Mari
Yamaguchi, “Japan to Scrap Costly Land-Based US Missile Defense System,” Yamaguchi, “Japan to Scrap Costly Land-Based US Missile Defense System,” Associated Press, June 15, 2020; Mike , June 15, 2020; Mike
Yeo, “Japan Suspends Aegis Ashore Deployment, Pointing to Cost and Technical Issues,” Yeo, “Japan Suspends Aegis Ashore Deployment, Pointing to Cost and Technical Issues,” Defense News, June 15, , June 15,
2020; Brad Glosserman, “Canceling Aegis Ashore Raises Problems—and Hopes,” 2020; Brad Glosserman, “Canceling Aegis Ashore Raises Problems—and Hopes,” Japan Times, June 17, 2020. , June 17, 2020.
Prior to the June 15, 2020, announcement, Japan had announced in early May that it would evaluate alternatives to the Prior to the June 15, 2020, announcement, Japan had announced in early May that it would evaluate alternatives to the
Akita Prefecture site due to strong local opposition to that site. (Masaya Kato, “Japan’s Missile Shield Deployment Akita Prefecture site due to strong local opposition to that site. (Masaya Kato, “Japan’s Missile Shield Deployment
Scuppered by Local Resistance,” Scuppered by Local Resistance,” Nikkei Asian Review, May 7, 2020.) , May 7, 2020.)
~~Congressional Research Service~~

9

~~Navy Aegis Ballistic Missile Defense (BMD) Program~~

~~Hamada confirmed that the defense ministry was accelerating the acquisition process to~~
~~get the two destroyers into service faster than usual.~~
~~“We believe it is an extremely important initiative to drastically strengthen our defense~~
~~capabilities within five years,” he said.33~~
~~A June 23, 2023, press report stated that once the two additional BMD-capable Aegis ships go~~
~~into service for dedicated BMD operations, Japan’s other eight BMD-capable destroyers will~~
~~revert to anti-air-warfare (AAW) operations.34~~
~~Use of Aegis BMD Elements in Guam Missile Defense Architecture~~
~~After studying various possible BMD system architectures for Guam, DOD proposed a system~~
~~combining elements of the Aegis BMD system with elements of Army BMD systems. A March~~
~~30, 2022, press report states~~
~~The Missile Defense Agency’s initial plan for the architecture to protect Guam turns to~~
~~proven systems to help the agency meet a 2026 fielding deadline, according Vice Adm.~~
~~Jon Hill, the agency’s director.~~
~~The defense of Guam from potential ballistic, cruise and hypersonic missile attacks has~~
~~become a priority for the MDA, which is seeking $539 million in fiscal 2023 to continue~~
33 See, for example, Thomas Newdick, “Japan’s Missile Defense Ships Will Now Be Multi-Role, Cruiser-Like,” The Drive, August 31, 2023; Yoshihiro Inaba, “Japan’s New ASEV Ships Will Boast An Impressive 128 VLS Cells,” Naval News, June 3, 2023. 34 Ridzwan Rahmat, “Japan to Revert Aegis Destroyers for Air-Defence Roles Once BMD Ships Come Online,” Janes Defence Weekly, June 23, 2023. Congressional Research Service 9 link to page 32 link to page 32 Navy Aegis Ballistic Missile Defense (BMD) Program to design and develop multiple-land based radar systems, procure weapon system to design and develop multiple-land based radar systems, procure weapon system
components and initiate military construction planning and design activity. components and initiate military construction planning and design activity.
“Current forces are capable of defending Guam against today’s North Korean ballistic “Current forces are capable of defending Guam against today’s North Korean ballistic
missile threats,” Dee Dee Martinez, the MDA’s comptroller said in a March 28 Pentagon missile threats,” Dee Dee Martinez, the MDA’s comptroller said in a March 28 Pentagon
budget briefing. “However, the regional threat to Guam, including from China, continues budget briefing. “However, the regional threat to Guam, including from China, continues
to rapidly evolve.”... to rapidly evolve.”...
The architecture will not be a fixed missile defense site like Aegis Ashore in Romania and The architecture will not be a fixed missile defense site like Aegis Ashore in Romania and
Poland, Hill said. “Think of it as a distributed system.” He added that the agency is Poland, Hill said. “Think of it as a distributed system.” He added that the agency is
interested in using mobile launchers. interested in using mobile launchers.
The architecture will include Navy SM-3 and SM-6 missiles, the Patriot air-and-missile The architecture will include Navy SM-3 and SM-6 missiles, the Patriot air-and-missile
defense system and the Army’s Terminal High Altitude Area Defense System (THAAD). defense system and the Army’s Terminal High Altitude Area Defense System (THAAD).
A THAAD battery has been operating on Guam since 2013. A THAAD battery has been operating on Guam since 2013.
Those elements will be connected through the Army’s Integrated Battle Command System, Those elements will be connected through the Army’s Integrated Battle Command System,
a command-and control-system that connects sensors and shooters on the battlefield. The a command-and control-system that connects sensors and shooters on the battlefield. The
agency will also use the Aegis weapon system’s fire control capability, Hill said. agency will also use the Aegis weapon system’s fire control capability, Hill said.
“Patriot [has] a fabulous capability for cruise missile defense, and that’s our first focus “Patriot [has] a fabulous capability for cruise missile defense, and that’s our first focus
area,” Hill said. “And we have the ability within Aegis to enable that, but, right now, we area,” Hill said. “And we have the ability within Aegis to enable that, but, right now, we
are doing ballistic missiles, hypersonic, on the Aegis part of that overall integrated are doing ballistic missiles, hypersonic, on the Aegis part of that overall integrated
architecture and then the cruise missile piece will be with the Army systems.” architecture and then the cruise missile piece will be with the Army systems.”
While MDA is focused on using existing technology to make up the architecture, it will While MDA is focused on using existing technology to make up the architecture, it will
consider new technology, including the Mid-Range Capability missile the Army will field consider new technology, including the Mid-Range Capability missile the Army will field
in FY23, as it becomes available, according to Hill.... in FY23, as it becomes available, according to Hill....

~~33 Dzirhan Mahadzir, “Japan to Build Two 20,000-ton Missile Defense Warships, Indian Carrier Commissions,”~~ ~~USNI~~
~~News, September 6, 2022. See also Yoshihiro Inaba, “New Details On Japan’s Future BMD Vessels Revealed,”~~ ~~Naval~~
~~News, September 12, 2022; Inder Singh Bisht, “Japan to Build Aegis-Equipped Ballistic Missile Defense Warships,”~~
Defense Post, September 15, 2022; Sam LaGrone, “Japanese MoD Releases New Details on Ballistic Missile Defense
~~Ships,” USNI News, December 27, 2022; Tyler Rogoway, “First Rendering Of Japan’s Ballistic Missile Defense Ship~~
~~Concept Released,” The Drive, December 29, 2022; Yoshihiro Inaba, “Japan’s New ASEV Ships Will Boast An~~
~~Impressive 128 VLS Cells,” Naval News, June 3, 2023.~~
~~34 Ridzwan Rahmat, “Japan to Revert Aegis Destroyers for Air-Defence Roles Once BMD Ships Come Online,”~~ ~~Janes~~
~~Defence Weekly, June 23, 2023.~~
~~Congressional Research Service~~

10

~~link to page 32 link to page 32~~ ~~Navy Aegis Ballistic Missile Defense (BMD) Program~~

“That topology of the island … it is a tough place,” Hill said. “An Aegis Ashore site is “That topology of the island … it is a tough place,” Hill said. “An Aegis Ashore site is
limited in what it can do because of the the rise and the fall of the hills, you got radar, it’s limited in what it can do because of the the rise and the fall of the hills, you got radar, it’s
not a flat earth, and it’s certainly not flat on Guam, so we’ve done some really incredible not a flat earth, and it’s certainly not flat on Guam, so we’ve done some really incredible
work and analysis over the last couple years ... by dispersing the systems and making sure work and analysis over the last couple years ... by dispersing the systems and making sure
everything’s networked.”35 everything’s networked.”35
Aegis BMD Development Philosophy and Flight Tests
The Aegis BMD development effort, including Aegis BMD flight tests, has been described as The Aegis BMD development effort, including Aegis BMD flight tests, has been described as
following a development philosophy long held within the Aegis program office of “build a little, following a development philosophy long held within the Aegis program office of “build a little,
test a little, learn a lot,” meaning that development is done in manageable steps, with each step test a little, learn a lot,” meaning that development is done in manageable steps, with each step
being tested and validated before moving on to the next step.36 For a summary of reported Aegis being tested and validated before moving on to the next step.36 For a summary of reported Aegis
BMD flight tests since 2002, seeBMD flight tests since 2002, see Table A-1 in tin the Appendix.
~~Allied Participation and Interest in Aegis BMD Program~~
~~Japan~~
~~Eight BMD-Capable Aegis Destroyers~~
~~Japan operates eight BMD-capable Aegis destroyers—the eighth was commissioned into service~~
~~in March 2021.37 As mentioned above, rather than building the two Aegis Ashore systems, Japan~~
~~now plans to instead build two additional BMD-capable Aegis ships that are to be dedicated to~~
~~BMD operations.38 As also mentioned above, a June 23, 2023, press report stated that once the~~
~~two additional BMD-capable Aegis ships go into service for dedicated BMD operations, Japan’s~~
~~other eight BMD-capable destroyers will revert to anti-air-warfare (AAW) operations.39 As also~~

35 Jen Judson, “MDA’s Plan to Protect Guam Relies on Field-Proven Systems,” 35 Jen Judson, “MDA’s Plan to Protect Guam Relies on Field-Proven Systems,” Defense News, March 30, 2022. See , March 30, 2022. See
also Jason Sherman, “OMB Reveals Land-Based VLS Also Part of New Guam Missile Defense Architecture,” also Jason Sherman, “OMB Reveals Land-Based VLS Also Part of New Guam Missile Defense Architecture,” Inside
Defense, July 13, 2022; Rich Abott, “MDA Decides On Guam Defense Architecture,” , July 13, 2022; Rich Abott, “MDA Decides On Guam Defense Architecture,” Defense Daily, March 29, 2022; , March 29, 2022;
Jason Sherman, “DOD Picks SPY-7 for Land-Based Aegis, Giving Lockheed First U.S. Customer for New Radar,” Jason Sherman, “DOD Picks SPY-7 for Land-Based Aegis, Giving Lockheed First U.S. Customer for New Radar,”
Inside Defense, May 6, 2022. , May 6, 2022.
36 See, for example, “Aegis BMD: “Build a Little, Test a Little, Learn a Lot,” USNI blog, March 15, 2010, accessed 36 See, for example, “Aegis BMD: “Build a Little, Test a Little, Learn a Lot,” USNI blog, March 15, 2010, accessed
May 18, 2022, at http://blog.usni.org/2010/03/15/aegis-bmd-build-a-little-test-a-little-learn-a-lot, and “Aegis Ballistic May 18, 2022, at http://blog.usni.org/2010/03/15/aegis-bmd-build-a-little-test-a-little-learn-a-lot, and “Aegis Ballistic
Missile Defense, Aegis Ballistic Missile Defense Overview for the George C. Marshall Institute, RADM Alan B. Missile Defense, Aegis Ballistic Missile Defense Overview for the George C. Marshall Institute, RADM Alan B.
Hicks, USN, Aegis BMD Program Director, August 3, 2009, slide 16 of 20, entitled “Some of our Philosophies In a Hicks, USN, Aegis BMD Program Director, August 3, 2009, slide 16 of 20, entitled “Some of our Philosophies In a
Nutshell (1 of 2),” accessed May 18, 2022, at https://web.archive.org/web/20100706133017/https:/www.marshall.org/Nutshell (1 of 2),” accessed May 18, 2022, at https://web.archive.org/web/20100706133017/https:/www.marshall.org/
pdf/materials/743.pdf. pdf/materials/743.pdf.
~~37 See, for example, Xavier Vavasseur, “Japan Commissions New Maya-Class AEGIS Destroyer JS Haguro はぐろ~~
~~DDG-180,” Naval News, March 19, 2021; Yomiuri Shimbun, “Japan Commissions 8th Aegis Destroyer Haguro,”~~ ~~Japan~~
~~News, March 20, 2021.~~
~~38 See, for example, Dzirhan Mahadzir, “Japan to Build Two 20,000-ton Missile Defense Warships, Indian Carrier~~
~~Commissions,” USNI News, September 6, 2022; Yoshihiro Inaba, “New Details On Japan’s Future BMD Vessels~~
~~Revealed,” Naval News, September 12, 2022; Inder Singh Bisht, “Japan to Build Aegis-Equipped Ballistic Missile~~
~~Defense Warships,” Defense Post, September 15, 2022; Sam LaGrone, “Japanese MoD Releases New Details on~~
~~Ballistic Missile Defense Ships,” USNI News, December 27, 2022; Tyler Rogoway, “First Rendering Of Japan’s~~
~~Ballistic Missile Defense Ship Concept Released,” The Drive, December 29, 2022; Yoshihiro Inaba, “Japan’s New~~
~~ASEV Ships Will Boast An Impressive 128 VLS Cells,” Naval News, June 3, 2023.~~
~~39 Ridzwan Rahmat, “Japan to Revert Aegis Destroyers for Air-Defence Roles Once BMD Ships Come Online,”~~ ~~Janes~~
~~Defence Weekly, June 23, 2023.~~
~~Congressional Research Service~~

11

~~link to page 32 link to page 32~~ ~~Navy Aegis Ballistic Missile Defense (BMD) Program~~

Congressional Research Service 10 link to page 32 link to page 32 Navy Aegis Ballistic Missile Defense (BMD) Program Allied Participation and Interest in Aegis BMD Program Japan Eight BMD-Capable Aegis Destroyers Japan operates eight BMD-capable Aegis destroyers—the eighth was commissioned into service in March 2021.37 As mentioned above, rather than building two Aegis Ashore systems, Japan now plans to instead build two additional BMD-capable Aegis ships. As also mentioned above, a June 23, 2023, press report stated that once the two additional BMD-capable Aegis ships go into service, Japan’s other eight BMD-capable destroyers will revert to anti-air-warfare (AAW) operations.38 As also mentioned above, Japanese BMD-capable Aegis ships have participated in some of the flight tests mentioned above, Japanese BMD-capable Aegis ships have participated in some of the flight tests
of the Aegis BMD system using the SM-3 interceptor (of the Aegis BMD system using the SM-3 interceptor (seesee Table A-1 inin Appendix)..40
39 Cooperative Development of SM-3 Block IIA Missile
As mentioned earlier, Japan cooperated with the United States on development the SM-3 Block As mentioned earlier, Japan cooperated with the United States on development the SM-3 Block
IIA missile. Japan developed certain technologies for the missile, and paid for the development of IIA missile. Japan developed certain technologies for the missile, and paid for the development of
those technologies, reducing the missile’s development costs for the United States. A July 6, those technologies, reducing the missile’s development costs for the United States. A July 6,
2018, press report states that “the U.S. and Japan are looking to jointly develop next-generation 2018, press report states that “the U.S. and Japan are looking to jointly develop next-generation
radar technology that would use Japanese semiconductors to more than double the detection radar technology that would use Japanese semiconductors to more than double the detection
range of the Aegis missile defense system.”range of the Aegis missile defense system.”41
~~South Korea~~
~~An October 12, 2018, press report states that “the South Korean military has decided to buy ship-~~
~~based SM-3 interceptors to thwart potential ballistic missile attacks from North Korea, a top~~
~~commander of the Joint Chiefs of Staff revealed Oct. 12.”42~~
~~Other Countries~~
~~Other countries that MDA views as potential naval BMD operators (using either the Aegis BMD~~
~~system or some other system of their own design) include the United Kingdom, the Netherlands,~~
~~Spain, Germany, Denmark, and Australia. Spain, South Korea, and Australia either operate, are~~
~~building, or are planning to build Aegis ships. The other countries operate destroyers and frigates~~
~~with different combat systems that may have potential for contributing to BMD operations.~~

4040 37 See, for example, Xavier Vavasseur, “Japan Commissions New Maya-Class AEGIS Destroyer JS Haguro はぐろ DDG-180,” Naval News, March 19, 2021; Yomiuri Shimbun, “Japan Commissions 8th Aegis Destroyer Haguro,” Japan News, March 20, 2021. 38 Ridzwan Rahmat, “Japan to Revert Aegis Destroyers for Air-Defence Roles Once BMD Ships Come Online,” Janes Defence Weekly, June 23, 2023. 39 Mari Yamaguchi (Associated Press), “Japan Confirms It’s Scrapping US Missile Defense System,” Mari Yamaguchi (Associated Press), “Japan Confirms It’s Scrapping US Missile Defense System,” Defense News, ,
June 25, 2020; Megan Eckstein, “Japan Officially Ends Aegis Ashore Plans After National Security Council June 25, 2020; Megan Eckstein, “Japan Officially Ends Aegis Ashore Plans After National Security Council
Deliberations,” Deliberations,” USNI News, June 26, 2020. , June 26, 2020.
See also Grant Newsham “Abe’s Aegis Ashore Cancellation Doesn’t Add Up,” See also Grant Newsham “Abe’s Aegis Ashore Cancellation Doesn’t Add Up,” Asia Times, June 30, 2020; Lucy Craft, , June 30, 2020; Lucy Craft,
“Why Japan Scrapped a $4 Billion Missile Defense Purchase from the U.S.,” “Why Japan Scrapped a $4 Billion Missile Defense Purchase from the U.S.,” CBS News, July 2, 2020; Tim Kelly, , July 2, 2020; Tim Kelly,
“Explainer: Strike Capability, Other Military Options on Table after Japan’s Aegis U-Turn,” “Explainer: Strike Capability, Other Military Options on Table after Japan’s Aegis U-Turn,” Reuters, July 2, 2020; , July 2, 2020;
Jeffrey W. Hornung, “Japan Is Canceling a U.S. Missile Defense System,” Jeffrey W. Hornung, “Japan Is Canceling a U.S. Missile Defense System,” Foreign Policy, July 2, 2020; Bruce , July 2, 2020; Bruce
Klingner, “Japan Undercuts Its Defense Against North Korean Missiles,” Heritage Foundation, July 22, 2020; Tim Klingner, “Japan Undercuts Its Defense Against North Korean Missiles,” Heritage Foundation, July 22, 2020; Tim
Kelly and Yoshifumi Takemoto, “Exclusive: As Japan Weighs Missile-Defence Options, Raytheon Lobbies for Kelly and Yoshifumi Takemoto, “Exclusive: As Japan Weighs Missile-Defence Options, Raytheon Lobbies for
Lockheed’s $300 Million Radar Deal,” Reuters, July 30, 2020; Rieko Miki, “The Price of Peace: Why Japan Scrapped Lockheed’s $300 Million Radar Deal,” Reuters, July 30, 2020; Rieko Miki, “The Price of Peace: Why Japan Scrapped
a $4.2bn US Missile System,” a $4.2bn US Missile System,” Nikkei Asian Review, August 5, 2020; Loren Thompson, “Japan’s Rethink Of Aegis , August 5, 2020; Loren Thompson, “Japan’s Rethink Of Aegis
Ashore Could Tie Up Navy, Increase Costs And Cause Big Delays,” Ashore Could Tie Up Navy, Increase Costs And Cause Big Delays,” Forbes, August 11, 2020. , August 11, 2020.
On June 18, 2020, it was reported that the United States and Japan were in talks to address the technical issues Japan On June 18, 2020, it was reported that the United States and Japan were in talks to address the technical issues Japan
cited and explore potential paths forward for bolstering Japan’s ballistic missile defense capability. See Lara Seligman, cited and explore potential paths forward for bolstering Japan’s ballistic missile defense capability. See Lara Seligman,
“U.S. and Japan in Talks about ‘Alternatives’ to Aegis Ashore Missile Defense System,” “U.S. and Japan in Talks about ‘Alternatives’ to Aegis Ashore Missile Defense System,” Politico Pro, June 18, 2020; , June 18, 2020;
Idrees Ali, “U.S. in Talks with Japan after Aegis Ashore Missile Defense System Suspension: Official,” Idrees Ali, “U.S. in Talks with Japan after Aegis Ashore Missile Defense System Suspension: Official,” Reuters, June , June
18, 2020; Jason Sherman, “MDA Hopes to ‘Resolve’ Japan’s Aegis Ashore Concerns, Reinstate Project,” 18, 2020; Jason Sherman, “MDA Hopes to ‘Resolve’ Japan’s Aegis Ashore Concerns, Reinstate Project,” Inside
Defense, June 18, 2020; “U.S. Talking with Japan on Concerns over Halted Missile Defense Plan,” , June 18, 2020; “U.S. Talking with Japan on Concerns over Halted Missile Defense Plan,” Kyodo News, June , June
19, 2020. See also Asahi Shimbun, “Japan Eyes Offshore Options to Replace Aegis Defense System,” 19, 2020. See also Asahi Shimbun, “Japan Eyes Offshore Options to Replace Aegis Defense System,” Asahi Shimbun, ,
September 10, 2020. September 10, 2020.
4140 Nikkei staff writers, “US Taps Japan Radar Tech to Double Missile Defense Range,” Nikkei staff writers, “US Taps Japan Radar Tech to Double Missile Defense Range,” Nikkei Asian Review, July 6, , July 6,
2018. 2018.
~~42 Jeff Jeong, “South Korea to Buy Ship-Based Interceptors to Counter Ballistic Missile Threats,” Defense News,~~
~~October 12, 2018.~~
~~Congressional Research Service~~

12

~~link to page 17~~ ~~Navy Aegis Ballistic Missile Defense (BMD) Program~~
Congressional Research Service 11 link to page 16 Navy Aegis Ballistic Missile Defense (BMD) Program South Korea An October 12, 2018, press report states that “the South Korean military has decided to buy ship-based SM-3 interceptors to thwart potential ballistic missile attacks from North Korea, a top commander of the Joint Chiefs of Staff revealed Oct. 12.”41 An October 16, 2023, press report states that South Korea’s newest Aegis destroyer will be BMD-capable.42 Other Countries Other countries that MDA views as potential naval BMD operators (using either the Aegis BMD system or some other system of their own design) include the United Kingdom, the Netherlands, Spain, Germany, Denmark, and Australia. Spain, South Korea, and Australia either operate, are building, or are planning to build Aegis ships. The other countries operate destroyers and frigates with different combat systems that may have potential for contributing to BMD operations.
FY2024-FY2028 MDA Procurement and R&D Funding
The Aegis BMD program is funded mostly through MDA’s budget. The Navy’s budget provides The Aegis BMD program is funded mostly through MDA’s budget. The Navy’s budget provides
additional funding for Aegis BMD-related effortsadditional funding for Aegis BMD-related efforts. Table 1 shows requested (FY2024) and shows requested (FY2024) and
projected (FY2025-FY2028) MDA procurement and research and development funding for Aegis projected (FY2025-FY2028) MDA procurement and research and development funding for Aegis
BMD efforts under MDA’s FY2024 budget submission. BMD efforts under MDA’s FY2024 budget submission.
Table 1. FY2024-FY2028 MDA Procurement and
R&D Funding for Aegis BMD Efforts
(In millions of dollars, rounded to nearest tenth; totals may not add due to rounding) (In millions of dollars, rounded to nearest tenth; totals may not add due to rounding)
FY24
FY25
FY26
FY27
FY28

(req.)
(proj.)
(proj.)
(proj.)
(proj.)
Procurement

Aegis BMD (line 33) Aegis BMD (line 33)
374.8 374.8
372.6 372.6
528.5 528.5
537.1 537.1
550.0 550.0
(SM-3 Block IB missile quantity)
(27)
(24)
(43)
(43)
(43)
Aegis BMD Advance Procurement (line 34) Aegis BMD Advance Procurement (line 34)
0 0
0 0
0 0
0 0
0 0
SM-3 Block IIA (line 36) SM-3 Block IIA (line 36)
432.8 432.8
507.7 507.7
464.1 464.1
457.9 457.9
467.1 467.1
(SM-3 Block IIA missile quantity)
(12)
(12)
(12)
(12)
(12)
Aegis Ashore Phase III (line 40) Aegis Ashore Phase III (line 40)
2.4 2.4
1.0 1.0
0 0
0 0
0 0
Aegis BMD hardware and software (line 42) Aegis BMD hardware and software (line 42)
27.8 27.8
44.9 44.9
28.4 28.4
35.5 35.5
31.8 31.8
SUBTOTAL Procurement
837.8
926.2
1,021.0
1,030.5
1,048.9
Research and development

Aegis BMD (PE 0603892C) (line 83) Aegis BMD (PE 0603892C) (line 83)
693.7 693.7
639.7 639.7
707.0 707.0
699.6 699.6
733.9 733.9
Aegis BMD Test (PE 0604878C) (line 114) Aegis BMD Test (PE 0604878C) (line 114)
193.5 193.5
135.5 135.5
183.0 183.0
203.7 203.7
135.1 135.1
Land-based SM-3 (PE 0604880C) (line 116) Land-based SM-3 (PE 0604880C) (line 116)
22.2 22.2
20.5 20.5
21.2 21.2
21.6 21.6
21.7 21.7
SUBTOTAL RDT&E
909.4
795.7
911.2
924.9
890.7
TOTAL
1,747.2
1,721.9
1,932.2
1,955.4
1,939.6
Source: Table prepared by CRS based on FY2024 MDA budget submission. Table prepared by CRS based on FY2024 MDA budget submission.
41 Jeff Jeong, “South Korea to Buy Ship-Based Interceptors to Counter Ballistic Missile Threats,” Defense News, October 12, 2018. 42 YoungHak Lee, “South Korea’s First KDX III Batch II Aegis Destroyer Started Sea Trials,” Naval News, October 16, 2023. Congressional Research Service 12 Navy Aegis Ballistic Missile Defense (BMD) Program Research and development funding in the table for the land-based SM-3 is funding for Aegis Research and development funding in the table for the land-based SM-3 is funding for Aegis
Ashore sites. MDA’s budget also includes additional funding not shown in the table for operations Ashore sites. MDA’s budget also includes additional funding not shown in the table for operations
and maintenance (O&M) and military construction (MilCon) for the Aegis BMD program. and maintenance (O&M) and military construction (MilCon) for the Aegis BMD program.
Issues for Congress
Annual Funding Request
One issue for Congress is whether to approve, reject, or modify MDA’s annual procurement and One issue for Congress is whether to approve, reject, or modify MDA’s annual procurement and
research and development funding requests for the program. In considering this issue, Congress research and development funding requests for the program. In considering this issue, Congress
may consider various factors, including whether the work that MDA is proposing to fund for the may consider various factors, including whether the work that MDA is proposing to fund for the
fiscal year in question is properly scoped and scheduled, and accurately priced. fiscal year in question is properly scoped and scheduled, and accurately priced.
Estimating and Reporting Costs
Another issue for Congress concerns the adequacy of MDA’s cost estimating and its reporting of Another issue for Congress concerns the adequacy of MDA’s cost estimating and its reporting of
costs. A February 2022 GAO report on MDA’s cost estimating and reporting of costs for missile costs. A February 2022 GAO report on MDA’s cost estimating and reporting of costs for missile
defense programs, including the Aegis BMD program, states defense programs, including the Aegis BMD program, states
~~Congressional Research Service~~

13

~~Navy Aegis Ballistic Missile Defense (BMD) Program~~

The Department of Defense’s (DOD) Missile Defense Agency (MDA) is continuing efforts The Department of Defense’s (DOD) Missile Defense Agency (MDA) is continuing efforts
to deliver systems to the warfighter that will protect against enemy missiles. However, to deliver systems to the warfighter that will protect against enemy missiles. However,
shortfalls persist with MDA’s program and flight test cost estimates and reporting. shortfalls persist with MDA’s program and flight test cost estimates and reporting.
Program cost estimates. MDA continues to omit the military services’ operations and MDA continues to omit the military services’ operations and
sustainment costs from the program life-cycle cost estimates.... By omitting these costs, sustainment costs from the program life-cycle cost estimates.... By omitting these costs,
MDA limits decision-makers’ insight into the full financial commitments needed for MDA limits decision-makers’ insight into the full financial commitments needed for
affordability and funding determinations.... affordability and funding determinations....
Flight test cost estimates. Accuracy issues linger with MDA’s flight test cost estimates that Accuracy issues linger with MDA’s flight test cost estimates that
could skew the agency’s annual $1.3 billion [flight test] funding request, such as not being could skew the agency’s annual $1.3 billion [flight test] funding request, such as not being
regularly updated with actual costs. However, MDA is taking steps to improve these cost regularly updated with actual costs. However, MDA is taking steps to improve these cost
estimates by using a new cost model, among other things.... estimates by using a new cost model, among other things....
Program cost reporting. MDA continues to adjust program baselines without clear MDA continues to adjust program baselines without clear
traceability over time. MDA also forgoes recurrent comparisons to the original baseline. traceability over time. MDA also forgoes recurrent comparisons to the original baseline.
Such adjustments and omissions impede decision-makers’ awareness of each program’s Such adjustments and omissions impede decision-makers’ awareness of each program’s
cost performance and total system cost.... cost performance and total system cost....
Flight test cost reporting. Congress required MDA to report on flight test costs, but we Congress required MDA to report on flight test costs, but we
found the information lacking due to the agency’s reporting methodology. MDA only found the information lacking due to the agency’s reporting methodology. MDA only
accounted for about $1.3 billion of at least $3.5 billion in funding the agency requested for accounted for about $1.3 billion of at least $3.5 billion in funding the agency requested for
flight testing between March 2017 and September 2020. Moreover, the reporting flight testing between March 2017 and September 2020. Moreover, the reporting
requirement ended in December 2021. Without further reporting on complete flight test requirement ended in December 2021. Without further reporting on complete flight test
costs, Congress does not have information needed to facilitate holding the agency costs, Congress does not have information needed to facilitate holding the agency
accountable for its spending.43 accountable for its spending.43
Potential for Intercepting ICBMs
Another issue for Congress is what role the Aegis BMD program should play in defending the Another issue for Congress is what role the Aegis BMD program should play in defending the
U.S. homeland against attack from ICBMs. With the advent of the SM-3 Block IIA interceptor, U.S. homeland against attack from ICBMs. With the advent of the SM-3 Block IIA interceptor,
DOD is evaluating the potential for the Aegis BMD system to intercept certain ICBMs. Section DOD is evaluating the potential for the Aegis BMD system to intercept certain ICBMs. Section
43 Government Accountability Office, Missile Defense[:] Addressing Cost Estimating and Reporting Shortfalls Could Improve Insight into Full Costs of Programs and Flight Tests, GAO-22-104344, February 2022, highlights page (PDF page 2 of 58). Congressional Research Service 13 Navy Aegis Ballistic Missile Defense (BMD) Program 1680 of the FY2018 National Defense Authorization Act (H.R. 2810/P.L. 115-91 of December 12, 1680 of the FY2018 National Defense Authorization Act (H.R. 2810/P.L. 115-91 of December 12,
2017) directed DOD to “conduct a test to evaluate and demonstrate, if technologically feasible, 2017) directed DOD to “conduct a test to evaluate and demonstrate, if technologically feasible,
the capability to defeat a simple intercontinental ballistic missile threat using the standard missile the capability to defeat a simple intercontinental ballistic missile threat using the standard missile
3 block IIA missile interceptor.” DOD’s January 2019 missile defense review report stated the 3 block IIA missile interceptor.” DOD’s January 2019 missile defense review report stated the
following: following:
The SM-3 Blk IIA interceptor is intended as part of the regional missile defense The SM-3 Blk IIA interceptor is intended as part of the regional missile defense
architecture, but also has the potential to provide an important “underlay” to existing GBIs architecture, but also has the potential to provide an important “underlay” to existing GBIs
[ground-based interceptors] for added protection against ICBM threats to the homeland. [ground-based interceptors] for added protection against ICBM threats to the homeland.
This interceptor has the potential to offer an additional defensive capability to ease the This interceptor has the potential to offer an additional defensive capability to ease the
burden on the GBI system and provide continuing protection for the U.S. homeland against burden on the GBI system and provide continuing protection for the U.S. homeland against
evolving rogue states’ long-range missile capabilities. evolving rogue states’ long-range missile capabilities.
Congress has directed DoD to examine the feasibility of the SM-3 Blk IIA against an Congress has directed DoD to examine the feasibility of the SM-3 Blk IIA against an
ICBM-class target. MDA will test this SM-3 Blk IIA capability in 2020. Due to the ICBM-class target. MDA will test this SM-3 Blk IIA capability in 2020. Due to the
mobility of sea-based assets, this new underlay capability will be surged in a crisis or mobility of sea-based assets, this new underlay capability will be surged in a crisis or
conflict to further thicken defensive capabilities for the U.S. homeland. Land-based sites conflict to further thicken defensive capabilities for the U.S. homeland. Land-based sites
in the United States with this SM-3 Blk IIA missile could also be pursued.44in the United States with this SM-3 Blk IIA missile could also be pursued.44

~~43 Government Accountability Office,~~ ~~Missile Defense[:] Addressing Cost Estimating and Reporting Shortfalls Could~~
~~Improve Insight into Full Costs of Programs and Flight Tests, GAO-22-104344, February 2022, highlights page (PDF~~
~~page 2 of 58).~~
~~44 Department of Defense, Missile Defense Review 2019, released January 17, 2019, p. 55. David Axe, “The U.S.~~
~~Navy’s New Missile Defense Is a Bad Idea,” National Interest, January 17, 2019.~~
~~Congressional Research Service~~

14

~~Navy Aegis Ballistic Missile Defense (BMD) Program~~

On November 16, 2020, MDA announced that the congressionally directed ICBM-intercept flight On November 16, 2020, MDA announced that the congressionally directed ICBM-intercept flight
test, called FTM-44, had been conducted on that date and had resulted in a successful intercept of test, called FTM-44, had been conducted on that date and had resulted in a successful intercept of
the ICBM-representative target. MDA stated that “FTM-44, originally scheduled for May 2020, the ICBM-representative target. MDA stated that “FTM-44, originally scheduled for May 2020,
was delayed due to restrictions in personnel and equipment movement intended to reduce the was delayed due to restrictions in personnel and equipment movement intended to reduce the
spread of COVID-19. FTM-44 satisfies a Congressional mandate to evaluate the feasibility of the spread of COVID-19. FTM-44 satisfies a Congressional mandate to evaluate the feasibility of the
SM-3 Block IIA missile’s capability to defeat an ICBM threat before the end of 2020.”45 A SM-3 Block IIA missile’s capability to defeat an ICBM threat before the end of 2020.”45 A
November 17, 2020, press report about the flight test stated that “the unarmed ICBM was a November 17, 2020, press report about the flight test stated that “the unarmed ICBM was a
replica of a target flown against the Ground-based Midcourse Defense system during a March replica of a target flown against the Ground-based Midcourse Defense system during a March
2019 flight test that featured a salvo launch of a pair of interceptors.”46 An April 2021 GAO 2019 flight test that featured a salvo launch of a pair of interceptors.”46 An April 2021 GAO
report on deliveries and testing of U.S. missile defense systems in FY2020 stated the following: report on deliveries and testing of U.S. missile defense systems in FY2020 stated the following:
MDA’s effort to include the SM-3 Block IIA interceptor in a new “layered” homeland MDA’s effort to include the SM-3 Block IIA interceptor in a new “layered” homeland
defense against intercontinental ballistic missile (ICBM) threats targeting the U.S. could defense against intercontinental ballistic missile (ICBM) threats targeting the U.S. could
introduce considerable cost, schedule, and performance uncertainty to a program that has introduce considerable cost, schedule, and performance uncertainty to a program that has
just entered initial production. The GMD weapon system currently provides defense just entered initial production. The GMD weapon system currently provides defense
against ICBMs, but this new effort would add the SM-3 Block IIA and THAAD weapon against ICBMs, but this new effort would add the SM-3 Block IIA and THAAD weapon
system as layers underneath that provided by GMD. For further details on the GMD and system as layers underneath that provided by GMD. For further details on the GMD and
THAAD weapon systems see their respective appendixes. THAAD weapon systems see their respective appendixes.
ICBM intercepts are more challenging than the IRBM intercepts for which the SM-3 IIA ICBM intercepts are more challenging than the IRBM intercepts for which the SM-3 IIA
was originally designed. MDA’s most recent attempt to create a system for intercepting was originally designed. MDA’s most recent attempt to create a system for intercepting
ICBMs, known as the Redesigned Kill Vehicle (RKV), re-used some parts from the SM-3 ICBMs, known as the Redesigned Kill Vehicle (RKV), re-used some parts from the SM-3
Block IIA. DOD cancelled the RKV before it could complete development after significant Block IIA. DOD cancelled the RKV before it could complete development after significant
cost and schedule overruns and questions about the ability of the design to overcome cost and schedule overruns and questions about the ability of the design to overcome
specific performance risks. Parts re-used from the SM-3 Block IIA were implicated in some specific performance risks. Parts re-used from the SM-3 Block IIA were implicated in some
of the RKV’s performance shortfalls. Even so, planning for an anti-ICBM capability for of the RKV’s performance shortfalls. Even so, planning for an anti-ICBM capability for
the SM-3 Block IIA continued during and even after the RKV’s termination. the SM-3 Block IIA continued during and even after the RKV’s termination.
Achieving such a capability will require surmounting several challenges. According to Achieving such a capability will require surmounting several challenges. According to
MDA, during the November 2020 flight test named FTM-44, the SM-3 Block IIA struck a MDA, during the November 2020 flight test named FTM-44, the SM-3 Block IIA struck a
simple ICBM target. This was not an operational test, however, and it was executed under simple ICBM target. This was not an operational test, however, and it was executed under
44 Department of Defense, Missile Defense Review 2019, released January 17, 2019, p. 55. David Axe, “The U.S. Navy’s New Missile Defense Is a Bad Idea,” National Interest, January 17, 2019. 45 Missile Defense Agency News release 20NEWS-0003, “U.S. Successfully Conducts SM-3 Block IIA Intercept Test Against an Intercontinental Ballistic Missile Target,” November 16, 2020. 46 Jason Sherman, “SM-3 Block IIA Intercepts ICBM Target, Validating Potential for Homeland Defense ‘Underlayer,’” Inside Defense, November 17, 2020. Congressional Research Service 14 Navy Aegis Ballistic Missile Defense (BMD) Program highly favorable conditions. More development work is needed for the SM-3 Block IIA to highly favorable conditions. More development work is needed for the SM-3 Block IIA to
support a layered homeland defense capability. MDA documents show that the agency now support a layered homeland defense capability. MDA documents show that the agency now
plans to develop and procure an upgraded version of the SM-3 Block IIA for the specific plans to develop and procure an upgraded version of the SM-3 Block IIA for the specific
purpose of fulfilling the homeland defense mission.47 purpose of fulfilling the homeland defense mission.47
A May 13, 2021, press report stated A May 13, 2021, press report stated
The Missile Defense Agency proved that a Navy destroyer with a Standard Missile-3 Block The Missile Defense Agency proved that a Navy destroyer with a Standard Missile-3 Block
IIA can stop a simple intercontinental ballistic missile threat, butIIA can stop a simple intercontinental ballistic missile threat, but more work remains to more work remains to
prove whether this combination could contribute to homeland defense, the MDA director prove whether this combination could contribute to homeland defense, the MDA director
said Wednesday [May 12]. said Wednesday [May 12].
Vice Adm. Jon Hill described the Flight Test Aegis Weapon System (FTM) 44, which took Vice Adm. Jon Hill described the Flight Test Aegis Weapon System (FTM) 44, which took
place in the Pacific in November after pandemic-related delays earlier in the year: A simple place in the Pacific in November after pandemic-related delays earlier in the year: A simple
ICBM target was launched from the Army’s Ronald Reagan Ballistic Missile Defense Test ICBM target was launched from the Army’s Ronald Reagan Ballistic Missile Defense Test
Site on the Kwajalein Atoll in the Marshall Islands. Satellites detected the launch, and a Site on the Kwajalein Atoll in the Marshall Islands. Satellites detected the launch, and a
slew of satellites and sensors, including on the Pacific Missile Range Facility in Hawaii, slew of satellites and sensors, including on the Pacific Missile Range Facility in Hawaii,
tracked the target. Arleigh Burke-class destroyer USS John Finn (DDG-113), positioned tracked the target. Arleigh Burke-class destroyer USS John Finn (DDG-113), positioned

~~45 Missile Defense Agency News release 20NEWS-0003, “U.S. Successfully Conducts SM-3 Block IIA Intercept Test~~
~~Against an Intercontinental Ballistic Missile Target,” November 16, 2020.~~
~~46 Jason Sherman, “SM-3 Block IIA Intercepts ICBM Target, Validating Potential for Homeland Defense~~
~~‘Underlayer,’” Inside Defense, November 17, 2020.~~
~~47 Government Accountability Office,~~ ~~Missile Defense[:] Fiscal Year 2020 Delivery and Testing Progressed, but~~
~~Annual Goals Unmet, GAO 21-314, April 2021, p. 24. See also Jen Judson, “Watchdog Expresses Concern over Using~~
~~US Navy Interceptor for Homeland Missile Defense,” Defense News, April 29, 2021.~~
~~Congressional Research Service~~

15

~~Navy Aegis Ballistic Missile Defense (BMD) Program~~

hundreds of miles east of Hawaii, launched an SM-3 Block IIA missile from its deck based hundreds of miles east of Hawaii, launched an SM-3 Block IIA missile from its deck based
on its best fire control solution at the time, and the missile itself maneuvered to successfully on its best fire control solution at the time, and the missile itself maneuvered to successfully
hit the target as it received more information in flight. hit the target as it received more information in flight.
The goal of the test, Hill said while speaking at the annual McAleese FY 2022 Defense The goal of the test, Hill said while speaking at the annual McAleese FY 2022 Defense
Programs Conference, was “to prove that we have the ability to leverage the robustness in Programs Conference, was “to prove that we have the ability to leverage the robustness in
the [Aegis] program, so that was really the first test just to see if it’s feasible. And we the [Aegis] program, so that was really the first test just to see if it’s feasible. And we
learned a lot.” learned a lot.”
Hill said the crew of John Finn, with limited data due to limited sensor coverage across the Hill said the crew of John Finn, with limited data due to limited sensor coverage across the
vast Pacific, maneuvered the ship to get the highest probability of kill. vast Pacific, maneuvered the ship to get the highest probability of kill.
“It maneuvered, shot the missile; lots of uncertainty because of lack of sensor coverage for “It maneuvered, shot the missile; lots of uncertainty because of lack of sensor coverage for
such a long-range flight where we were doing the exercise. So what we actually saw was a such a long-range flight where we were doing the exercise. So what we actually saw was a
really high divert [from the missile]. So kind of two walkaways from that first test, which really high divert [from the missile]. So kind of two walkaways from that first test, which
is why I think it was really important, was that it was the longest propagated error or is why I think it was really important, was that it was the longest propagated error or
uncertainty that we’ve ever seen in any test. And then we had the highest divert—that uncertainty that we’ve ever seen in any test. And then we had the highest divert—that
meant the [SM-3 IIA] missile was maneuvering to actually take it out, and it still took it meant the [SM-3 IIA] missile was maneuvering to actually take it out, and it still took it
out, which is really great,” Hill continued. out, which is really great,” Hill continued.
“In terms of feasibility, did we accomplish the mission? Absolutely. Every test objective “In terms of feasibility, did we accomplish the mission? Absolutely. Every test objective
achieved in November.” achieved in November.”
Hill was asked about an April Government Accountability Office report that cited concerns Hill was asked about an April Government Accountability Office report that cited concerns
about the Aegis Combat System/SM-3 IIA pairing for the homeland defense mission—as about the Aegis Combat System/SM-3 IIA pairing for the homeland defense mission—as
opposed to the regional defense mission it was built for, to protect a high-value asset such opposed to the regional defense mission it was built for, to protect a high-value asset such
as an aircraft carrier from an intermediate-range missile—and whether the simple ICBM as an aircraft carrier from an intermediate-range missile—and whether the simple ICBM
target used in the November test was representative of the real world. target used in the November test was representative of the real world.
“So what’s next? What’s next is to go against a more complex intercontinental ballistic “So what’s next? What’s next is to go against a more complex intercontinental ballistic
missile threat, and maybe even change the scenario. This scenario was a defense of Hawaii missile threat, and maybe even change the scenario. This scenario was a defense of Hawaii
scenario against a rogue nation—you guess which one out there in the Pacific—and in the scenario against a rogue nation—you guess which one out there in the Pacific—and in the
future we’re going to go to a more complex [threat], and that’s within the next couple future we’re going to go to a more complex [threat], and that’s within the next couple
years,” he said. years,” he said.
“So we’re still analyzing data from November, and then we’re going to make upgrades and “So we’re still analyzing data from November, and then we’re going to make upgrades and
changes to the combat system, and we’ll make changes to the missile in terms of threat set changes to the combat system, and we’ll make changes to the missile in terms of threat set
to take on a higher end class threat.” to take on a higher end class threat.”
47 Government Accountability Office, Missile Defense[:] Fiscal Year 2020 Delivery and Testing Progressed, but Annual Goals Unmet, GAO 21-314, April 2021, p. 24. See also Jen Judson, “Watchdog Expresses Concern over Using US Navy Interceptor for Homeland Missile Defense,” Defense News, April 29, 2021. Congressional Research Service 15 Navy Aegis Ballistic Missile Defense (BMD) Program MDA and the military services would have to further integrate systems together to make MDA and the military services would have to further integrate systems together to make
this a credible layer in the homeland defense network, Hill said. During the November test, this a credible layer in the homeland defense network, Hill said. During the November test,
the MDA commanded and controlled the event from the Missile Defense Interoperability the MDA commanded and controlled the event from the Missile Defense Interoperability
and Operations Center in Colorado Springs, Colo., using the Command and Control Battle and Operations Center in Colorado Springs, Colo., using the Command and Control Battle
Management and Communication System (C2BMC) to receive satellite and sensor data Management and Communication System (C2BMC) to receive satellite and sensor data
and feed it to John Finn, which fired its missile on remote without having access to the and feed it to John Finn, which fired its missile on remote without having access to the
sensor data itself. While that worked in a controlled environment, for a permanent sensor data itself. While that worked in a controlled environment, for a permanent
homeland defense mission the ship would need to be better integrated into U.S. Northern homeland defense mission the ship would need to be better integrated into U.S. Northern
Command’s network to fully share information and targeting data. Command’s network to fully share information and targeting data.
Hill said that Aegis has been integrated to operate with the Terminal High Altitude Area Hill said that Aegis has been integrated to operate with the Terminal High Altitude Area
Defense system, and THAAD has been integrated with the Patriot missile defense system, Defense system, and THAAD has been integrated with the Patriot missile defense system,
but MDA hasn’t integrated all the regional defense systems with homeland defense but MDA hasn’t integrated all the regional defense systems with homeland defense
systems. systems.
Beyond the actual integration and engineering work, Hill added that there was a policy Beyond the actual integration and engineering work, Hill added that there was a policy
question to answer, too. question to answer, too.
“Do we want ships in that role of being off the West Coast … defending against ICBMs as “Do we want ships in that role of being off the West Coast … defending against ICBMs as
a layer to the Ground-Based Mid-Course Defense? That’s an incredible conversation, a layer to the Ground-Based Mid-Course Defense? That’s an incredible conversation,
we’re having that now, and it’s hard to predict where it will go.” we’re having that now, and it’s hard to predict where it will go.”
~~Congressional Research Service~~

16

~~Navy Aegis Ballistic Missile Defense (BMD) Program~~

Asked on Thursday during the Naval Postgraduate School’s acquisition research Asked on Thursday during the Naval Postgraduate School’s acquisition research
symposium if the Navy has the capacity and appetite to use destroyers for homeland symposium if the Navy has the capacity and appetite to use destroyers for homeland
defense, Hill said much of it comes down to what ships are available for the mission. defense, Hill said much of it comes down to what ships are available for the mission.
“I think if you asked Gen. [Glen] VanHerck from NORTHCOM about his confidence in “I think if you asked Gen. [Glen] VanHerck from NORTHCOM about his confidence in
defending the nation today, the answer would be confident. But as the threat evolves, right, defending the nation today, the answer would be confident. But as the threat evolves, right,
you start to see a little change in that view. And so it’s been viewed for a while that the you start to see a little change in that view. And so it’s been viewed for a while that the
Navy can play a role in that area, but it becomes an asset problem,” Hill said. “There are Navy can play a role in that area, but it becomes an asset problem,” Hill said. “There are
only so many ships we have up there. And they’re multi-mission ships, and they have a lot only so many ships we have up there. And they’re multi-mission ships, and they have a lot
of roles around the globe to execute.”48 of roles around the globe to execute.”48
A June 22, 2021, press report stated A June 22, 2021, press report stated
The Pentagon’s No. 2 official has ordered 11 missile interceptors transferred from research The Pentagon’s No. 2 official has ordered 11 missile interceptors transferred from research
and development for possible deployment on Navy ships in the Pacific or European regions and development for possible deployment on Navy ships in the Pacific or European regions
after a test in November indicated they could stop an intercontinental ballistic missile. after a test in November indicated they could stop an intercontinental ballistic missile.
In the test, the USS John Finn intercepted a mock ICBM intended to simulate one that In the test, the USS John Finn intercepted a mock ICBM intended to simulate one that
could be launched at Hawaii by North Korea. The destroyer, operating near Hawaii, fired could be launched at Hawaii by North Korea. The destroyer, operating near Hawaii, fired
off one of the Standard Missile-3 model Block IIA interceptors built by Raytheon off one of the Standard Missile-3 model Block IIA interceptors built by Raytheon
Technologies Corp. at the target launched from Kwajalein Atoll in the Marshall Islands. Technologies Corp. at the target launched from Kwajalein Atoll in the Marshall Islands.
Deputy Defense Secretary Kathleen Hicks informed Congress May 27 of her rationale for Deputy Defense Secretary Kathleen Hicks informed Congress May 27 of her rationale for
transferring the interceptors, although she didn’t disclose it publicly. transferring the interceptors, although she didn’t disclose it publicly.
“The missiles have conducted successful intercept tests and their deployment is in the “The missiles have conducted successful intercept tests and their deployment is in the
important interest of our national security,” Hicks spokesman Jamal Brown said in an email important interest of our national security,” Hicks spokesman Jamal Brown said in an email
this month. The transfer to the Navy marks the first major missile defense initiative of the this month. The transfer to the Navy marks the first major missile defense initiative of the
Biden administration. Biden administration.
Although the Navy’s Aegis combat system, which launched the missile, and the interceptor Although the Navy’s Aegis combat system, which launched the missile, and the interceptor
“were not designed to defeat an ICBM-class target, this test demonstrated some potential “were not designed to defeat an ICBM-class target, this test demonstrated some potential
48 Megan Eckstein, “MDA: Test of DDG, Standard Missile-3 IIA a Good Start, But More Work Needed on Homeland Defense Mission,” USNI News, May 13, 2021. See also Jason Sherman, “MDA Planning Second SM-3 Block IIA Flight Test Against ICBM Target; New Development and Upgraded Interceptor Needed,” Inside Defense, May 12, 2021; Rich Abott, “MDA Planning Second Test of SM-3 IIA Against ICBM Target,” Defense Daily, May 17, 2021. Congressional Research Service 16 Navy Aegis Ballistic Missile Defense (BMD) Program limited capability,” Vice Admiral Jon Hill, director of the Missile Defense Agency, said in limited capability,” Vice Admiral Jon Hill, director of the Missile Defense Agency, said in
testimony to Congress last week.49 testimony to Congress last week.49
Required vs. Available Numbers of BMD-Capable Aegis Ships
Another potential issue for Congress concerns required versus available numbers of BMD-Another potential issue for Congress concerns required versus available numbers of BMD-
capable Aegis ships. Some observers have expressed concern about the potential operational capable Aegis ships. Some observers have expressed concern about the potential operational
implications of a shortfall in the available number of BMD-capable relative to the required implications of a shortfall in the available number of BMD-capable relative to the required
number. Regarding the required number of BMD-capable Aegis ships, an August 15, 2018, Navy number. Regarding the required number of BMD-capable Aegis ships, an August 15, 2018, Navy
information paper states the following: information paper states the following:
The [Navy’s] 2016 Force Structure Assessment [FSA]50 sets the requirement [for BMD- The [Navy’s] 2016 Force Structure Assessment [FSA]50 sets the requirement [for BMD-
capable ships] at 54 BMD-capable ships, as part of the 104 large surface combatant capable ships] at 54 BMD-capable ships, as part of the 104 large surface combatant
requirement, to meet Navy unique requirements to support defense of the sea base and requirement, to meet Navy unique requirements to support defense of the sea base and
limited expeditionary land base sites…. limited expeditionary land base sites….

~~48 Megan Eckstein, “MDA: Test of DDG, Standard Missile-3 IIA a Good Start, But More Work Needed on Homeland~~
~~Defense Mission,” USNI News, May 13, 2021. See also Jason Sherman, “MDA Planning Second SM-3 Block IIA~~
~~Flight Test Against ICBM Target; New Development and Upgraded Interceptor Needed,” Inside Defense, May 12,~~
~~2021; Rich Abott, “MDA Planning Second Test of SM-3 IIA Against ICBM Target,” Defense Daily, May 17, 2021.~~
~~49 Anthony Capaccio, “U.S. Navy Ships Close to Getting Interceptors That Could Stop an ICBM,” Bloomberg, June 22,~~
~~2021.~~
~~50 The FSA is the Navy’s analysis, performed every few years, that establishes the Navy’s ship force structure~~
~~requirements. For further discussion, see CRS Report RL32665,~~ ~~Navy Force Structure and Shipbuilding Plans:~~
~~Background and Issues for Congress, by Ronald O'Rourke.~~
~~Congressional Research Service~~

17

~~Navy Aegis Ballistic Missile Defense (BMD) Program~~

The minimum requirement for 54 BMD ships is based on the Navy unique requirement as The minimum requirement for 54 BMD ships is based on the Navy unique requirement as
follows. It accepts risk in the sourcing of combatant commander (CCDR) requests for follows. It accepts risk in the sourcing of combatant commander (CCDR) requests for
defense of land. defense of land.
- 30 to meet CVN escort demand for rotational deployment of the carrier strike groups - 30 to meet CVN escort demand for rotational deployment of the carrier strike groups
- 11 INCONUS for independent BMD deployment demand - 11 INCONUS for independent BMD deployment demand
- 9 in forward deployed naval forces (FDNF) Japan to meet operational timelines in - 9 in forward deployed naval forces (FDNF) Japan to meet operational timelines in
USINDOPACOM USINDOPACOM
- 4 in FDNF Europe for rotational deployment in EUCOM.51 - 4 in FDNF Europe for rotational deployment in EUCOM.51
Burden of BMD Mission on U.S. Navy Aegis Ships
A related potential issue for Congress is the burden that BMD operations may be placing on the A related potential issue for Congress is the burden that BMD operations may be placing on the
Navy’s fleet of Aegis ships, particularly since performing BMD patrols requires those ships to Navy’s fleet of Aegis ships, particularly since performing BMD patrols requires those ships to
operate in geographic locations that may be unsuitable for performing other U.S. Navy missions, operate in geographic locations that may be unsuitable for performing other U.S. Navy missions,
and whether there are alternative ways to perform BMD missions now performed by U.S. Navy and whether there are alternative ways to perform BMD missions now performed by U.S. Navy
Aegis ships, such as establishing more Aegis Ashore sites. A June 16, 2018, press report states the Aegis ships, such as establishing more Aegis Ashore sites. A June 16, 2018, press report states the
following: following:
The U.S. Navy’s top officer wants to end standing ballistic missile defense patrols and The U.S. Navy’s top officer wants to end standing ballistic missile defense patrols and
transfer the mission to shore-based assets. transfer the mission to shore-based assets.
Chief of Naval Operations Adm. John Richardson said in no uncertain terms on June 12 Chief of Naval Operations Adm. John Richardson said in no uncertain terms on June 12
that he wants the Navy off the tether of ballistic missile defense patrols, a mission that has that he wants the Navy off the tether of ballistic missile defense patrols, a mission that has
put a growing strain on the Navy’s hard-worn surface combatants, and the duty shifted put a growing strain on the Navy’s hard-worn surface combatants, and the duty shifted
towards more shore-based infrastructure. towards more shore-based infrastructure.
“Right now, as we speak, I have six multi-mission, very sophisticated, dynamic cruisers “Right now, as we speak, I have six multi-mission, very sophisticated, dynamic cruisers
and destroyers―six of them are on ballistic missile defense duty at sea,” Richardson said and destroyers―six of them are on ballistic missile defense duty at sea,” Richardson said
49 Anthony Capaccio, “U.S. Navy Ships Close to Getting Interceptors That Could Stop an ICBM,” Bloomberg, June 22, 2021. 50 The FSA is the Navy’s analysis, performed every few years, that establishes the Navy’s ship force structure requirements. For further discussion, see CRS Report RL32665, Navy Force Structure and Shipbuilding Plans: Background and Issues for Congress, by Ronald O'Rourke. 51 Navy information paper dated August 15, 2018, entitled “Ballistic Missile Defense (BMD) Capable Ships requirement,” provided by Navy Office of Legislative Affairs to CBO and CRS on August 15, 2018. The information paper was requested by CBO. Congressional Research Service 17 Navy Aegis Ballistic Missile Defense (BMD) Program during his address at the U.S. Naval War College’s Current Strategy Forum. “And if you during his address at the U.S. Naval War College’s Current Strategy Forum. “And if you
know a little bit about this business you know that geometry is a tyrant. know a little bit about this business you know that geometry is a tyrant.
“You have to be in a tiny little box to have a chance at intercepting that incoming missile. “You have to be in a tiny little box to have a chance at intercepting that incoming missile.
So, we have six ships that could go anywhere in the world, at flank speed, in a tiny little So, we have six ships that could go anywhere in the world, at flank speed, in a tiny little
box, defending land.” box, defending land.”
Richardson continued, saying the Navy could be used in emergencies but that in the long Richardson continued, saying the Navy could be used in emergencies but that in the long
term the problem demands a different solution. term the problem demands a different solution.
“It’s a pretty good capability and if there is an emergent need to provide ballistic missile “It’s a pretty good capability and if there is an emergent need to provide ballistic missile
defense, we’re there,” he said. “But 10 years down the road, it’s time to build something defense, we’re there,” he said. “But 10 years down the road, it’s time to build something
on land to defend the land. Whether that’s AEGIS ashore or whatever, I want to get out of on land to defend the land. Whether that’s AEGIS ashore or whatever, I want to get out of
the long-term missile defense business and move to dynamic missile defense.” the long-term missile defense business and move to dynamic missile defense.”
The unusually direct comments from the CNO come amid growing frustration among the The unusually direct comments from the CNO come amid growing frustration among the
surface warfare community that the mission, which requires ships to stay in a steaming box surface warfare community that the mission, which requires ships to stay in a steaming box
doing figure-eights for weeks on end, is eating up assets and operational availability that doing figure-eights for weeks on end, is eating up assets and operational availability that
could be better used confronting growing high-end threats from China and Russia. could be better used confronting growing high-end threats from China and Russia.
The BMD mission was also a factor in degraded readiness in the surface The BMD mission was also a factor in degraded readiness in the surface fleet. Amid the fleet. Amid the
nuclear threat from North Korea, the BMD mission began eating more and more of the nuclear threat from North Korea, the BMD mission began eating more and more of the
readiness generated in the Japan-based U.S. 7th Fleet, which created a pressurized situation readiness generated in the Japan-based U.S. 7th Fleet, which created a pressurized situation
that caused leaders in the Pacific to cut corners and sacrifice training time for their crews, that caused leaders in the Pacific to cut corners and sacrifice training time for their crews,

~~51 Navy information paper dated August 15, 2018, entitled “Ballistic Missile Defense (BMD) Capable Ships~~
~~requirement,” provided by Navy Office of Legislative Affairs to CBO and CRS on August 15, 2018. The information~~
~~paper was requested by CBO.~~
~~Congressional Research Service~~

18

~~Navy Aegis Ballistic Missile Defense (BMD) Program~~

an environment described in the Navy’s comprehensive review into the two collisions that an environment described in the Navy’s comprehensive review into the two collisions that
claimed the lives of 17 sailors in the disastrous summer of 2017. claimed the lives of 17 sailors in the disastrous summer of 2017.
Richardson said that as potential enemies double down on anti-access technologies Richardson said that as potential enemies double down on anti-access technologies
designed to keep the U.S. Navy at bay, the Navy needed to focus on missile defense for its designed to keep the U.S. Navy at bay, the Navy needed to focus on missile defense for its
own assets. own assets.
“We’re going to need missile defense at sea as we kind of fight our way now into the battle “We’re going to need missile defense at sea as we kind of fight our way now into the battle
spaces we need to get into,” he said. “And so restoring dynamic maneuver has something spaces we need to get into,” he said. “And so restoring dynamic maneuver has something
to do with missile defense.52 to do with missile defense.52
A June 23, 2018, press report states the following: A June 23, 2018, press report states the following:
The threats from a resurgent Russia and rising China―which is cranking out ships like it’s The threats from a resurgent Russia and rising China―which is cranking out ships like it’s
preparing for war―have put enormous pressure on the now-aging [U.S. Navy Aegis preparing for war―have put enormous pressure on the now-aging [U.S. Navy Aegis
destroyer] fleet. Standing requirements for BMD patrols have put increasing strain on the destroyer] fleet. Standing requirements for BMD patrols have put increasing strain on the
U.S. Navy’s surface ships. U.S. Navy’s surface ships.
The Navy now stands at a crossroads. BMD, while a burden, has also been a cash cow that The Navy now stands at a crossroads. BMD, while a burden, has also been a cash cow that
has pushed the capabilities of the fleet exponentially forward over the past decade. The has pushed the capabilities of the fleet exponentially forward over the past decade. The
game-changing SPY-6 air and missile defense radar destined for DDG Flight III, for game-changing SPY-6 air and missile defense radar destined for DDG Flight III, for
example, is a direct response to the need for more advanced BMD shooters. But a smaller example, is a direct response to the need for more advanced BMD shooters. But a smaller
fleet, needed for everything from anti-submarine patrols to freedom-of-navigation missions fleet, needed for everything from anti-submarine patrols to freedom-of-navigation missions
in the South China Sea, routinely has a large chunk tethered to BMD missions. in the South China Sea, routinely has a large chunk tethered to BMD missions.
“Right now, as we speak, I have six multimission, very sophisticated, dynamic cruisers and “Right now, as we speak, I have six multimission, very sophisticated, dynamic cruisers and
destroyers―six of them are on ballistic missile defense duty at sea,” Chief of Naval destroyers―six of them are on ballistic missile defense duty at sea,” Chief of Naval
Operations Adm. John Richardson said during an address at the recent U.S. Naval War Operations Adm. John Richardson said during an address at the recent U.S. Naval War
College’s Current Strategy Forum. “You have to be in a tiny little box to have a chance at College’s Current Strategy Forum. “You have to be in a tiny little box to have a chance at
intercepting that incoming missile. So we have six ships that could go anywhere in the intercepting that incoming missile. So we have six ships that could go anywhere in the
world, at flank speed, in a tiny little box, defending land.” world, at flank speed, in a tiny little box, defending land.”
52 David B. Larter, “The US Navy Is Fed Up with Ballistic Missile Defense Patrols,” Defense News, June 16, 2018. See also Paul McLeary, “Will Budget Crunch Pentagon Laser & Space Investments?” Breaking Defense, November 13, 2018. Congressional Research Service 18 Navy Aegis Ballistic Missile Defense (BMD) Program And for every six ships the Navy has deployed in a standing mission, it means 18 ships are And for every six ships the Navy has deployed in a standing mission, it means 18 ships are
in various stages of the deployment cycle preparing to relieve them. in various stages of the deployment cycle preparing to relieve them.
The Pentagon, led by Defense Secretary Jim Mattis, wants the Navy to be more flexible The Pentagon, led by Defense Secretary Jim Mattis, wants the Navy to be more flexible
and less predictable―“dynamic” is the buzzword of moment in Navy circles. What and less predictable―“dynamic” is the buzzword of moment in Navy circles. What
Richardson is proposing is moving standing requirements for BMD patrols away from Richardson is proposing is moving standing requirements for BMD patrols away from
ships underway and all the associated costs that incurs, and toward fixed, shore-based sites, ships underway and all the associated costs that incurs, and toward fixed, shore-based sites,
and also surging the Navy’s at-sea BMD capabilities when there is an active threat.... and also surging the Navy’s at-sea BMD capabilities when there is an active threat....
In a follow-up response to questions posed on the CNO’s comments, Navy spokesman In a follow-up response to questions posed on the CNO’s comments, Navy spokesman
Cmdr. William Speaks said the Navy’s position is that BMD is an integral part of the Cmdr. William Speaks said the Navy’s position is that BMD is an integral part of the
service’sservice’s mission, but where long-term threats exist, the Navy should “consider a more mission, but where long-term threats exist, the Navy should “consider a more
persistent, land-based solution as an option.” persistent, land-based solution as an option.”
“This idea is not about the nation’s or the Navy’s commitment to BMD for the U.S. and “This idea is not about the nation’s or the Navy’s commitment to BMD for the U.S. and
our allies and partners―the Navy’s commitment to ballistic missile defense is rock-solid,” our allies and partners―the Navy’s commitment to ballistic missile defense is rock-solid,”
Speaks said. “In fact, the Navy will grow the number of BMD-capable ships from 38 to 60 Speaks said. “In fact, the Navy will grow the number of BMD-capable ships from 38 to 60
by 2023, in response to the growing demand for this capability. by 2023, in response to the growing demand for this capability.
“The idea is about how to best meet that commitment. In alignment with our national “The idea is about how to best meet that commitment. In alignment with our national
strategic documents, we have shifted our focus in an era of great power competition―this strategic documents, we have shifted our focus in an era of great power competition―this
calls us to think innovatively about how best to meet the demands of this mission and calls us to think innovatively about how best to meet the demands of this mission and
optimize the power of the joint force.”... optimize the power of the joint force.”...

~~52 David B. Larter, “The US Navy Is Fed Up with Ballistic Missile Defense Patrols,” Defense News, June 16, 2018. See~~
~~also Paul McLeary, “Will Budget Crunch Pentagon Laser & Space Investments?” Breaking Defense, November 13,~~
~~2018.~~
~~Congressional Research Service~~

19

~~Navy Aegis Ballistic Missile Defense (BMD) Program~~

While the idea of saving money by having fixed BMD sites and freeing up multimission While the idea of saving money by having fixed BMD sites and freeing up multimission
ships is sensible, it may have unintended consequences, said Bryan McGrath, a retired ships is sensible, it may have unintended consequences, said Bryan McGrath, a retired
destroyer skipper and owner of the defense consultancy The FerryBridge Group. destroyer skipper and owner of the defense consultancy The FerryBridge Group.
“The BMD mission is part of what creates the force structure requirement for large surface “The BMD mission is part of what creates the force structure requirement for large surface
combatants,” McGrath said on Twitter after Defense News reported the CNO’s comments. combatants,” McGrath said on Twitter after Defense News reported the CNO’s comments.
“Absent it, the number of CG’s and DDG’s would necessarily decline. This may in fact be “Absent it, the number of CG’s and DDG’s would necessarily decline. This may in fact be
desirable, depending on the emerging fleet architecture and the roles and missions debate desirable, depending on the emerging fleet architecture and the roles and missions debate
underway. Perhaps we need more smaller, multi-mission ships than larger, more expensive underway. Perhaps we need more smaller, multi-mission ships than larger, more expensive
ones. ones.
“But it cannot be forgotten that while the mission is somewhat wasteful of a capable, multi- “But it cannot be forgotten that while the mission is somewhat wasteful of a capable, multi-
mission ship, the fact that we have built the ships that (among other things) do this mission mission ship, the fact that we have built the ships that (among other things) do this mission
is an incredibly good thing. If there is a penalty to be paid in peacetime sub-optimization is an incredibly good thing. If there is a penalty to be paid in peacetime sub-optimization
in order to have wartime capacity—should this not be considered a positive thing?” in order to have wartime capacity—should this not be considered a positive thing?”
McGrath went on to say that the suite of combat systems that have been built into Aegis McGrath went on to say that the suite of combat systems that have been built into Aegis
have been in response to the BMD threat. And indeed, the crown jewels of the surface have been in response to the BMD threat. And indeed, the crown jewels of the surface
fleet―Aegis Baseline 9 software, which allows a ship to do both air defense and BMD fleet―Aegis Baseline 9 software, which allows a ship to do both air defense and BMD
simultaneously; the Aegis common-source library; the forthcoming SPY-6; cooperative simultaneously; the Aegis common-source library; the forthcoming SPY-6; cooperative
engagement―have come about either in part or entirely driven by the BMD mission.... engagement―have come about either in part or entirely driven by the BMD mission....
A Navy official who spoke on condition of anonymity, to discuss the Navy’s shifting A Navy official who spoke on condition of anonymity, to discuss the Navy’s shifting
language on BMD, acknowledged the tone had shifted since the 2000s when the Navy language on BMD, acknowledged the tone had shifted since the 2000s when the Navy
latched onto the mission. But the official added that the situation more than a decade later latched onto the mission. But the official added that the situation more than a decade later
has dramatically shifted. has dramatically shifted.
“The strategic environment has changed significantly since the early 2000s―particularly “The strategic environment has changed significantly since the early 2000s―particularly
in the western Pacific. We have never before faced multiple peer rivals in a world as in the western Pacific. We have never before faced multiple peer rivals in a world as
interconnected and interdependent as we do today,” the official said. “Nor have we ever interconnected and interdependent as we do today,” the official said. “Nor have we ever
seen technologies that could alter the character of war as dramatically as those we see seen technologies that could alter the character of war as dramatically as those we see
emerging around us. China and Russia have observed our way of war and are on the move emerging around us. China and Russia have observed our way of war and are on the move
to reshape the environment to their favor.” to reshape the environment to their favor.”
In response to the threat and Defense Secretary Jim Mattis’ desire to use the force more In response to the threat and Defense Secretary Jim Mattis’ desire to use the force more
dynamically, the Navy is looking at its options, the official said. “This includes taking a dynamically, the Navy is looking at its options, the official said. “This includes taking a
Congressional Research Service 19 Navy Aegis Ballistic Missile Defense (BMD) Program look at how we employ BMD ships through the lens of great power competition to compete, look at how we employ BMD ships through the lens of great power competition to compete,
deter and win against those who threaten us.”53 deter and win against those who threaten us.”53
A January 29, 2019, press report states the following: A January 29, 2019, press report states the following:
The Navy is looking to get out of the missile defense business, the service’s top admiral The Navy is looking to get out of the missile defense business, the service’s top admiral
said today, and the Pentagon’s new missile defense review might give the service the off-said today, and the Pentagon’s new missile defense review might give the service the off-
ramp it has been looking for to stop sailing in circles waiting for ground-based missile ramp it has been looking for to stop sailing in circles waiting for ground-based missile
launches. launches.
This wasn’t the first time Adm. John Richardson bristled in public over his ships sailing in This wasn’t the first time Adm. John Richardson bristled in public over his ships sailing in
“small boxes” at sea tasked with protecting land, when they could be out performing other “small boxes” at sea tasked with protecting land, when they could be out performing other
missions challenging Chinese and Russian adventurism in the South China Sea and the missions challenging Chinese and Russian adventurism in the South China Sea and the
North Atlantic…. North Atlantic….
“We’ve got exquisite capability, but we’ve had ships protecting some pretty static assets “We’ve got exquisite capability, but we’ve had ships protecting some pretty static assets
on land for a decade,” Richardson said at the Brookings Institute. “If that [stationary] asset on land for a decade,” Richardson said at the Brookings Institute. “If that [stationary] asset
is going to be a long-term protected asset, then let’s build something on land and protect is going to be a long-term protected asset, then let’s build something on land and protect
that and liberate these ships from this mission.” that and liberate these ships from this mission.”
Japan is already moving down the path of building up a more robust ground-based sensor Japan is already moving down the path of building up a more robust ground-based sensor
and shooter layer, while also getting its own ships out to sea armed with the Aegis radar and shooter layer, while also getting its own ships out to sea armed with the Aegis radar

~~53 David B. Larter, “As Threats Mount, US Navy Grapples with Costly Ballistic Missile Defense Mission,”~~ ~~Defense~~
~~News, June 23, 2018.~~
~~Congressional Research Service~~

20

~~Navy Aegis Ballistic Missile Defense (BMD) Program~~

and missile defense system, both of which would free up American hulls from what and missile defense system, both of which would free up American hulls from what
Richardson on Monday called “the small [geographic] boxes where they have to stay for Richardson on Monday called “the small [geographic] boxes where they have to stay for
ballistic missile defense.”54 ballistic missile defense.”54
Allied Burden Sharing: U.S. vs. Allied Contributions to Regional
BMD Capabilities
Another related potential issue for Congress concerns allied burden sharing—how allied Another related potential issue for Congress concerns allied burden sharing—how allied
contributions to regional BMD capabilities and operations compare to U.S. naval contributions to contributions to regional BMD capabilities and operations compare to U.S. naval contributions to
overseas regional BMD capabilities and operations, particularly in light of constraints on U.S. overseas regional BMD capabilities and operations, particularly in light of constraints on U.S.
defense spending, worldwide operational demands for U.S. Navy Aegis ships, and calls by some defense spending, worldwide operational demands for U.S. Navy Aegis ships, and calls by some
U.S. observers for increased allied defense efforts. The issue can arise in connection with both U.S. observers for increased allied defense efforts. The issue can arise in connection with both
U.S. allies in Europe and U.S. allies in Asia. Regarding U.S. allies in Asia, a December 12, 2018, U.S. allies in Europe and U.S. allies in Asia. Regarding U.S. allies in Asia, a December 12, 2018,
press report states the following: press report states the following:
In June, US Navy Chief of Naval Operations (CNO) Admiral John Richardson said during In June, US Navy Chief of Naval Operations (CNO) Admiral John Richardson said during
a speech at the US Naval War College that the US Navy should terminate its current a speech at the US Naval War College that the US Navy should terminate its current
practice of dedicating several US Navy warships solely for Ballistic Missile Defense practice of dedicating several US Navy warships solely for Ballistic Missile Defense
(BMD). (BMD).
Richardson wanted US warships to halt BMD patrols off Japan and Europe as they are Richardson wanted US warships to halt BMD patrols off Japan and Europe as they are
limiting, restrictive missions that could be better accomplished by existing land-based limiting, restrictive missions that could be better accomplished by existing land-based
BMD systems such as Patriot anti-missile batteries, the US Terminal High Altitude Area BMD systems such as Patriot anti-missile batteries, the US Terminal High Altitude Area
Defense (THAAD) anti-missile system and the Aegis Ashore anti-missile system. Defense (THAAD) anti-missile system and the Aegis Ashore anti-missile system.
In the months since dropping his bombshell, Richardson—and much of the debate—has In the months since dropping his bombshell, Richardson—and much of the debate—has
gone quiet. gone quiet.
“My guess is the CNO got snapped back by the Pentagon for exceeding where the debate “My guess is the CNO got snapped back by the Pentagon for exceeding where the debate
actually stood,” one expert on US naval affairs told Asia Times. actually stood,” one expert on US naval affairs told Asia Times.
53 David B. Larter, “As Threats Mount, US Navy Grapples with Costly Ballistic Missile Defense Mission,” Defense News, June 23, 2018. 54 Paul McLeary, “The Navy Has Had Enough of Missile Defense And Sees Its Chance,” Breaking Defense, January 28, 2019. Congressional Research Service 20 Navy Aegis Ballistic Missile Defense (BMD) Program But others agree with him. Air Force Lt Gen Samuel A Greaves, the director of the US But others agree with him. Air Force Lt Gen Samuel A Greaves, the director of the US
Missile Defense Agency (MDA), acknowledges Richardson’s attempts to highlight how Missile Defense Agency (MDA), acknowledges Richardson’s attempts to highlight how
these BMD patrols were placing unwelcome “strain on the (US Navy’s) crews and these BMD patrols were placing unwelcome “strain on the (US Navy’s) crews and
equipment.” equipment.”
But there are complications. While it may free US Navy warships for sea-control, rather But there are complications. While it may free US Navy warships for sea-control, rather
than land defense, there is a concern that next- generation hypersonic cruise missiles could than land defense, there is a concern that next- generation hypersonic cruise missiles could
defeat land-based BMD systems, such as Aegis Ashore, while the US Navy’s Aegis-defeat land-based BMD systems, such as Aegis Ashore, while the US Navy’s Aegis-
equipped warships offer the advantages of high-speed mobility and stealth, resulting in equipped warships offer the advantages of high-speed mobility and stealth, resulting in
greater survivability overall. greater survivability overall.
As Japan prepares to acquire its first Aegis Ashore BMD system – and perhaps other As Japan prepares to acquire its first Aegis Ashore BMD system – and perhaps other
systems such as the THAAD system which has been deployed previously in Romania and systems such as the THAAD system which has been deployed previously in Romania and
South Korea – the possibility that the US Navy will end its important BMD role represents South Korea – the possibility that the US Navy will end its important BMD role represents
abrupt change…. abrupt change….
Japan’s decision to deploy Aegis Ashore can fill in any gap created by a possible US Navy Japan’s decision to deploy Aegis Ashore can fill in any gap created by a possible US Navy
cessation of BMD patrols. “The land-based option is more reliable, less logistically cessation of BMD patrols. “The land-based option is more reliable, less logistically
draining, and despite being horrendously expensive, could be effective in the sense that it draining, and despite being horrendously expensive, could be effective in the sense that it
provides a degree of reassurance to the Japanese people and US government, and provides a degree of reassurance to the Japanese people and US government, and
introduces an element of doubt of missile efficacy into [North Korean] calculations,” said introduces an element of doubt of missile efficacy into [North Korean] calculations,” said
[Garren Mulloy, Associate Professor of International Relations at Daito Bunka University [Garren Mulloy, Associate Professor of International Relations at Daito Bunka University
in Saitama, Japan], adding, however, that these systems could not cover Okinawa. in Saitama, Japan], adding, however, that these systems could not cover Okinawa.

~~54 Paul McLeary, “The Navy Has Had Enough of Missile Defense And Sees Its Chance,” Breaking Defense, January~~
~~28, 2019.~~
~~Congressional Research Service~~

21

~~Navy Aegis Ballistic Missile Defense (BMD) Program~~

“Fixed sites in Japan could be vulnerable, and the Aegis vessels provide a flexible forward- “Fixed sites in Japan could be vulnerable, and the Aegis vessels provide a flexible forward-
defense, before anything enters Japanese airspace, but with obviously limited reactions defense, before anything enters Japanese airspace, but with obviously limited reactions
times,” Mulloy said. “Aegis Ashore gives more reaction time – but over Japanese times,” Mulloy said. “Aegis Ashore gives more reaction time – but over Japanese
airspace.”… airspace.”…
The silence about this sudden possible shift in the US defense posture in the western Pacific The silence about this sudden possible shift in the US defense posture in the western Pacific
is understandable: it is a sensitive topic in Washington and Tokyo. However, the Trump is understandable: it is a sensitive topic in Washington and Tokyo. However, the Trump
administration has urged its allies to pay more for their own defense needs and to support administration has urged its allies to pay more for their own defense needs and to support
US troops deployed overseas. US troops deployed overseas.
Meanwhile, Tokyo needs to proceed cautiously given the likelihood that neighbors might Meanwhile, Tokyo needs to proceed cautiously given the likelihood that neighbors might
view a move on BMD as evidence that Tokyo is adopting an increasingly aggressive view a move on BMD as evidence that Tokyo is adopting an increasingly aggressive
defense posture in the region. defense posture in the region.
But for them, it is a no-win situation. If the US does ditch the BMD patrol mission, China But for them, it is a no-win situation. If the US does ditch the BMD patrol mission, China
and North Korea might view the shift as equally menacing given that it greatly enhances and North Korea might view the shift as equally menacing given that it greatly enhances
the US Navy’s maritime warfare capabilities.55 the US Navy’s maritime warfare capabilities.55
Conversion of Hawaii Aegis Test Site
Another potential issue for Congress is whether to convert the Aegis test facility in Hawaii into an Another potential issue for Congress is whether to convert the Aegis test facility in Hawaii into an
operational land-based Aegis BMD site. DOD’s January 2019 missile defense review report operational land-based Aegis BMD site. DOD’s January 2019 missile defense review report
states, in a section on improving or adapting existing BMD systems, that states, in a section on improving or adapting existing BMD systems, that
Another repurposing option is to operationalize, either temporarily or permanently, the Another repurposing option is to operationalize, either temporarily or permanently, the
Aegis Ashore Missile Defense Test Center in Kauai, Hawaii, to strengthen the defense of Aegis Ashore Missile Defense Test Center in Kauai, Hawaii, to strengthen the defense of
Hawaii against North Korean missile capabilities. DoD will study this possibility to further Hawaii against North Korean missile capabilities. DoD will study this possibility to further
evaluate it as a viable near-term option to enhance the defense of Hawaii. The United States evaluate it as a viable near-term option to enhance the defense of Hawaii. The United States
will augment the defense of Hawaii in order to stay ahead of any possible North Korean will augment the defense of Hawaii in order to stay ahead of any possible North Korean
missile threat. MDA and the Navy will evaluate the viability of this option and develop an missile threat. MDA and the Navy will evaluate the viability of this option and develop an
Emergency Activation Plan that would enable the Secretary of Defense to operationalize Emergency Activation Plan that would enable the Secretary of Defense to operationalize
the Aegis Ashore test site in Kauai within 30 days of the Secretary’s decision to do so, the the Aegis Ashore test site in Kauai within 30 days of the Secretary’s decision to do so, the
steps that would need to be taken, associated costs, and personnel requirements. This plan steps that would need to be taken, associated costs, and personnel requirements. This plan
55 Peter J. Brown, “Japan, US Silent over Ending Ballistic Missile Patrols,” Asia Times, December 12, 2018. Congressional Research Service 21 Navy Aegis Ballistic Missile Defense (BMD) Program will be delivered to USDA&S, USDR&E, and USDP within six months of the release of will be delivered to USDA&S, USDR&E, and USDP within six months of the release of
the MDR.56 the MDR.56
A January 25, 2019, press report states the following: A January 25, 2019, press report states the following:
The Defense Department will examine the funding breakdown between the Navy and the The Defense Department will examine the funding breakdown between the Navy and the
Missile Defense Agency should the government make Hawaii’s Aegis Ashore Missile Missile Defense Agency should the government make Hawaii’s Aegis Ashore Missile
Defense Test Center into an operational resource, according to the agency’s director. Defense Test Center into an operational resource, according to the agency’s director.
“Today, it involves both Navy resources for the operational crews—that man that site—as “Today, it involves both Navy resources for the operational crews—that man that site—as
well as funds that come to MDA for research, development and test production and well as funds that come to MDA for research, development and test production and
sustainment,” Lt. Gen. Sam Greaves said of the test center when asked how the funding sustainment,” Lt. Gen. Sam Greaves said of the test center when asked how the funding
would shake out between the Navy and MDA should the Pentagon move forward with the would shake out between the Navy and MDA should the Pentagon move forward with the
recommendation.57 recommendation.57
Potential Contribution from Lasers
Another potential issue for Congress concerns the potential for ship-based lasers to contribute in Another potential issue for Congress concerns the potential for ship-based lasers to contribute in
coming years to Navy terminal-phase BMD operations and the impact this might eventually have coming years to Navy terminal-phase BMD operations and the impact this might eventually have

~~55 Peter J. Brown, “Japan, US Silent over Ending Ballistic Missile Patrols,” Asia Times, December 12, 2018.~~
~~56 Department of Defense, Missile Defense Review 2019, released January 17, 2019, pp. 55-56.~~
~~57 Mallory Shelbourne, “DOD to Determine Funding Breakdown for Aegis Ashore Repurposing,” Inside the Navy,~~
~~January 25, 2019.~~
~~Congressional Research Service~~

22

~~Navy Aegis Ballistic Missile Defense (BMD) Program~~

on required numbers of ship-based BMD interceptor missiles. Another CRS report discusses the on required numbers of ship-based BMD interceptor missiles. Another CRS report discusses the
potential value of ship-based lasers for performing various missions, including, potentially, potential value of ship-based lasers for performing various missions, including, potentially,
terminal-phase BMD operations.58 terminal-phase BMD operations.58
Program Deliveries, Testing, and Technical Risk
Another potential oversight issue for Congress concerns deliveries, testing, and technical risk in Another potential oversight issue for Congress concerns deliveries, testing, and technical risk in
the Aegis BMD program. the Aegis BMD program.
May 2023 GAO Report
A May 2023 GAO report on U.S. BMD systems, including the Aegis BMD system, stated the A May 2023 GAO report on U.S. BMD systems, including the Aegis BMD system, stated the
following: following:
DELIVERIES DELIVERIES
MDA did not meet its fiscal year 2022 goal for SM-3 Block IB interceptors as five planned MDA did not meet its fiscal year 2022 goal for SM-3 Block IB interceptors as five planned
interceptors were delivered after the fiscal year ended. MDA, however, delivered nine interceptors were delivered after the fiscal year ended. MDA, however, delivered nine
backlogged interceptors that were previously delayed due to a flight test failure. The Aegis backlogged interceptors that were previously delayed due to a flight test failure. The Aegis
program temporarily halted deliveries to investigate the failure, but missile production did program temporarily halted deliveries to investigate the failure, but missile production did
not stop and deliveries subsequently resumed. not stop and deliveries subsequently resumed.
MDA also did not meet its goal for SM-3 Block IIA interceptors. Three interceptors MDA also did not meet its goal for SM-3 Block IIA interceptors. Three interceptors
planned for fiscal year 2022 were not delivered. MDA was able to deliver six backlogged planned for fiscal year 2022 were not delivered. MDA was able to deliver six backlogged
interceptors that we previously reported were delayed due to missile assembly issues. The interceptors that we previously reported were delayed due to missile assembly issues. The
Aegis program addressed the issues, which allowed them to resume deliveries. Aegis program addressed the issues, which allowed them to resume deliveries.
As reported by the agency, in August 2022, the Director, MDA approved an acquisition As reported by the agency, in August 2022, the Director, MDA approved an acquisition
strategy to align SM-3 Block IB and Block IIA production under one contract. This strategy to align SM-3 Block IB and Block IIA production under one contract. This
production alignment is expected to maximize efficiencies in program management and production alignment is expected to maximize efficiencies in program management and
obsolescence monitoring, among other synergies. According to MDA officials, they have obsolescence monitoring, among other synergies. According to MDA officials, they have
not identified any disadvantages with this strategy. This acquisition strategy is currently not identified any disadvantages with this strategy. This acquisition strategy is currently
56 Department of Defense, Missile Defense Review 2019, released January 17, 2019, pp. 55-56. 57 Mallory Shelbourne, “DOD to Determine Funding Breakdown for Aegis Ashore Repurposing,” Inside the Navy, January 25, 2019. 58 See CRS Report R44175, Navy Shipboard Lasers: Background and Issues for Congress, by Ronald O'Rourke. Congressional Research Service 22 Navy Aegis Ballistic Missile Defense (BMD) Program under review by the Under Secretary of Defense for Acquisition and Sustainment to under review by the Under Secretary of Defense for Acquisition and Sustainment to
support a production decision for SM-3 Block IIA. support a production decision for SM-3 Block IIA.
TESTING TESTING
Aegis BMD conducted four flight tests in fiscal year 2022, including a successful intercept Aegis BMD conducted four flight tests in fiscal year 2022, including a successful intercept
test event that demonstrated its interoperability with Japanese and Korean systems. The test event that demonstrated its interoperability with Japanese and Korean systems. The
last test—Flight Test Experiment Aegis Weapon System-01—gathered data while an SM-last test—Flight Test Experiment Aegis Weapon System-01—gathered data while an SM-
3 Block IIA interceptor engaged a modified medium range ballistic missile target in a non-3 Block IIA interceptor engaged a modified medium range ballistic missile target in a non-
intercept test. intercept test.
Aegis BMD conducted two planned ground tests. Ground Test Integrated (GTI)-09 Sprint Aegis BMD conducted two planned ground tests. Ground Test Integrated (GTI)-09 Sprint
1 provided data to support decisions related to system capabilities affecting United States 1 provided data to support decisions related to system capabilities affecting United States
European Command and United States Central Command. GTI-ISR 21 assessed the European Command and United States Central Command. GTI-ISR 21 assessed the
system’s interoperability with Israeli missile defense systems. Aegis BMD also system’s interoperability with Israeli missile defense systems. Aegis BMD also
participated in GTI-08a—a delayed test originally planned for fiscal year 2020—which participated in GTI-08a—a delayed test originally planned for fiscal year 2020—which
provided data to support system capabilities decisions for Aegis and other missile defense provided data to support system capabilities decisions for Aegis and other missile defense
system elements. system elements.
A planned Aegis BMD operational cyber test was delayed to fiscal year 2024 due to A planned Aegis BMD operational cyber test was delayed to fiscal year 2024 due to
MDA’s changes to its test plan that affected planned ground and cyber tests. MDA’s changes to its test plan that affected planned ground and cyber tests.
OTHER PROGRAM INFORMATION OTHER PROGRAM INFORMATION
Aegis Ashore

~~58 See CRS Report R44175, Navy Shipboard Lasers: Background and Issues for Congress, by Ronald O'Rourke.~~
~~Congressional Research Service~~

23

~~Navy Aegis Ballistic Missile Defense (BMD) Program~~

We reported in June 2022 that delivery of the Aegis Ashore system to Poland was originally We reported in June 2022 that delivery of the Aegis Ashore system to Poland was originally
planned for fiscal year 2018, but that construction challenges delayed delivery.1 Total planned for fiscal year 2018, but that construction challenges delayed delivery.1 Total
projected costs increased by 12 percent, including additional costs for retaining engineering projected costs increased by 12 percent, including additional costs for retaining engineering
and security services during the delays. The site remains under construction, but MDA and security services during the delays. The site remains under construction, but MDA
officials stated there are no known technical risks. In addition, the Aegis Ashore program officials stated there are no known technical risks. In addition, the Aegis Ashore program
recently met key milestones. Specifically, Aegis Light Off occurred in June 2022, which recently met key milestones. Specifically, Aegis Light Off occurred in June 2022, which
signifies the initial powering up of the weapon system to observe if all integrated systems signifies the initial powering up of the weapon system to observe if all integrated systems
are operational. The program completed physical installation of the system and are operational. The program completed physical installation of the system and
demonstrated it in October 2022. MDA expects to declare the site safe and technically demonstrated it in October 2022. MDA expects to declare the site safe and technically
capable in early 2023 and Navy acceptance is anticipated for later in the year. capable in early 2023 and Navy acceptance is anticipated for later in the year.
Safe Service Life Extension
The Aegis program has been able to extend the safe service life of SM-3 Block IA and The Aegis program has been able to extend the safe service life of SM-3 Block IA and
Block IB interceptors to ensure the interceptors can be used with no additional safety risk. Block IB interceptors to ensure the interceptors can be used with no additional safety risk.
Under this effort, the safe service life of Block IA interceptors increased from 12 to 18 Under this effort, the safe service life of Block IA interceptors increased from 12 to 18
years and Block IB interceptors increased from 8 to 12 years. The safe service life of Block years and Block IB interceptors increased from 8 to 12 years. The safe service life of Block
IIA interceptors is currently 12 years and MDA is assessing the possibility to increase this IIA interceptors is currently 12 years and MDA is assessing the possibility to increase this
to 16, or possibly up to 20, years. MDA officials described the process to extend an to 16, or possibly up to 20, years. MDA officials described the process to extend an
interceptor’s safe service life, which includes testing and analysis of aged missile interceptor’s safe service life, which includes testing and analysis of aged missile
components to determine their suitability for extended service. The testing and analysis is components to determine their suitability for extended service. The testing and analysis is
conducted by industry and government stakeholders and subject matter experts at various conducted by industry and government stakeholders and subject matter experts at various
locations and laboratories. MDA officials said safe service life extensions have helped locations and laboratories. MDA officials said safe service life extensions have helped
address the challenge of meeting the Navy’s interceptor inventory requirements, which address the challenge of meeting the Navy’s interceptor inventory requirements, which
typically entail high volume procurements and consistent repair and recertification typically entail high volume procurements and consistent repair and recertification
throughput. throughput.
Software Development
MDA officials stated the Navy started implementing a multi-stage Development, Security, MDA officials stated the Navy started implementing a multi-stage Development, Security,
and Operations strategy to deliver software upgrades to Aegis platforms. The Navy started and Operations strategy to deliver software upgrades to Aegis platforms. The Navy started
using a software factory—an automated process to develop software—in fiscal year 2021 using a software factory—an automated process to develop software—in fiscal year 2021
and now plans to eliminate their legacy system for developing and delivering coded and now plans to eliminate their legacy system for developing and delivering coded
software capability in fiscal year 2024.2 According to MDA officials, by fiscal year 2030 software capability in fiscal year 2024.2 According to MDA officials, by fiscal year 2030
the Navy intends for this approach to be the sole means for developing and delivering coded the Navy intends for this approach to be the sole means for developing and delivering coded
Congressional Research Service 23 Navy Aegis Ballistic Missile Defense (BMD) Program software capability to all Aegis platforms. MDA officials explained this strategy provides software capability to all Aegis platforms. MDA officials explained this strategy provides
the opportunity to significantly increase the speed of software deliveries to the fleet, as well the opportunity to significantly increase the speed of software deliveries to the fleet, as well
as reduce costs and cybersecurity risk by integrating security functions in the development as reduce costs and cybersecurity risk by integrating security functions in the development
process. They stated, however, there is risk since it is a significant transition from current process. They stated, however, there is risk since it is a significant transition from current
development strategies. They said the transition would require extensive retraining and development strategies. They said the transition would require extensive retraining and
hiring of government personnel to fully execute the strategy, as well as additional costs to hiring of government personnel to fully execute the strategy, as well as additional costs to
develop the new required tools, such as software, models, and infrastructure.59 develop the new required tools, such as software, models, and infrastructure.59
Regarding the development of a capability for the SM-6 to intercept hypersonic missiles, the Regarding the development of a capability for the SM-6 to intercept hypersonic missiles, the
GAO report stated: GAO report stated:
MDA has two main efforts under development to defend against hypersonic weapons: MDA has two main efforts under development to defend against hypersonic weapons:
• Glide Phase Intercept (GPI) is a program that includes a missile being designed to be fired • Glide Phase Intercept (GPI) is a program that includes a missile being designed to be fired
from Aegis-equipped ships to intercept a hypersonic weapon in the middle (or “glide”) from Aegis-equipped ships to intercept a hypersonic weapon in the middle (or “glide”)
phase of its flight path. phase of its flight path.
• Hypersonic and Ballistic Tracking Space Sensor (HBTSS) is an effort to develop space- • Hypersonic and Ballistic Tracking Space Sensor (HBTSS) is an effort to develop space-
based sensors to track and support the intercept of a hypersonic weapon…. based sensors to track and support the intercept of a hypersonic weapon….
GPI is expected to work with existing and future systems to provide hypersonic defense. GPI is expected to work with existing and future systems to provide hypersonic defense.
After a missile launch, SDA’s wide field of view satellites, capable of viewing large After a missile launch, SDA’s wide field of view satellites, capable of viewing large

~~59 Government Accountability Office, Missile Defense[:] Annual Goals Unmet for Deliveries and Testing, GAO-23-~~
~~106011, May 2023, pp. 22-23.~~
~~Congressional Research Service~~

24

~~Navy Aegis Ballistic Missile Defense (BMD) Program~~

portions of the globe, detect the threat launch and send sensor measurement data to BOA, portions of the globe, detect the threat launch and send sensor measurement data to BOA,
which generates track data with accuracy sufficient to cue HBTSS. HBTSS then acquires which generates track data with accuracy sufficient to cue HBTSS. HBTSS then acquires
the deployed Hypersonic Glide Vehicle (HGV) and collects precision angle measurements. the deployed Hypersonic Glide Vehicle (HGV) and collects precision angle measurements.
These measurements are processed by HBTSS, BOA, and Command, Control, Battle These measurements are processed by HBTSS, BOA, and Command, Control, Battle
Management, and Communications (C2BMC) to provide fire control quality tracks on the Management, and Communications (C2BMC) to provide fire control quality tracks on the
HGV to Aegis for support of an engagement using GPI…. HGV to Aegis for support of an engagement using GPI….
GPI STATUS AND CHALLENGES GPI STATUS AND CHALLENGES
Events and Milestones
By the early 2030s, the GPI program plans to deliver a prototype capability for testing, By the early 2030s, the GPI program plans to deliver a prototype capability for testing,
demonstration data to inform further development, and 10 interceptors to be used for demonstration data to inform further development, and 10 interceptors to be used for
testing. The program established a plan to acquire the capability and identified key events testing. The program established a plan to acquire the capability and identified key events
and milestones for tracking development. The plan includes competitive development of and milestones for tracking development. The plan includes competitive development of
the GPI missile leveraging multiple contractors to begin the effort, but only one contractor the GPI missile leveraging multiple contractors to begin the effort, but only one contractor
is anticipated to be selected to complete delivery of the prototype capability. In fiscal year is anticipated to be selected to complete delivery of the prototype capability. In fiscal year
2022, MDA reported that three contractors were awarded Other Transaction Agreements 2022, MDA reported that three contractors were awarded Other Transaction Agreements
to initiate work on the GPI program.1 Later, in the fiscal year the program reported to initiate work on the GPI program.1 Later, in the fiscal year the program reported
selecting two contractors to continue the development of GPI into the next phase of the selecting two contractors to continue the development of GPI into the next phase of the
acquisition process, technology development. In fiscal year 2023, the program expects to acquisition process, technology development. In fiscal year 2023, the program expects to
focus efforts on technology maturity and applying top level requirements to component focus efforts on technology maturity and applying top level requirements to component
level designs in preparation for the Preliminary Design Review…. level designs in preparation for the Preliminary Design Review….
The Preliminary Design Review is currently planned by the end of fiscal year 2027. The The Preliminary Design Review is currently planned by the end of fiscal year 2027. The
GPI program also anticipates down-selecting from two to one contractor near this date to GPI program also anticipates down-selecting from two to one contractor near this date to
continue until completing delivery of the prototype capability…. continue until completing delivery of the prototype capability….
Challenges
Previously we found in June 2022 that MDA had not planned to conduct an Independent Previously we found in June 2022 that MDA had not planned to conduct an Independent
Cost Estimate (ICE) or Independent Technical Risk Assessment (ITRA) for the GPI Cost Estimate (ICE) or Independent Technical Risk Assessment (ITRA) for the GPI
program before the product development phase, which is after the technology development program before the product development phase, which is after the technology development
phase. These assessments are required for certain elements by DOD Directive-Type phase. These assessments are required for certain elements by DOD Directive-Type
Memorandum 20-002 to mitigate risk. Since our reporting, MDA officials stated the Office Memorandum 20-002 to mitigate risk. Since our reporting, MDA officials stated the Office
of Cost Assessment and Program Evaluation (CAPE) completed a preliminary ICE for the of Cost Assessment and Program Evaluation (CAPE) completed a preliminary ICE for the
59 Government Accountability Office, Missile Defense[:] Annual Goals Unmet for Deliveries and Testing, GAO-23-106011, May 2023, pp. 22-23. Congressional Research Service 24 link to page 30 Navy Aegis Ballistic Missile Defense (BMD) Program GPI program in the August 2022 timeframe. As of February 2023, CAPE is working to GPI program in the August 2022 timeframe. As of February 2023, CAPE is working to
finalize the ICE pending the final President’s Budget program schedule. MDA officials finalize the ICE pending the final President’s Budget program schedule. MDA officials
also stated the Office of the Under Secretary of Defense for Research and Engineering also stated the Office of the Under Secretary of Defense for Research and Engineering
completed an ITRA for the GPI program in the August 2022 timeframe as well. According completed an ITRA for the GPI program in the August 2022 timeframe as well. According
to MDA, the ITRA found that the program should address technical risks earlier in the to MDA, the ITRA found that the program should address technical risks earlier in the
development schedule by building and testing hardware. The ITRA also recommended development schedule by building and testing hardware. The ITRA also recommended
earlier testing. We plan to review the ICE and ITRA to assess whether MDA has acquired earlier testing. We plan to review the ICE and ITRA to assess whether MDA has acquired
knowledge to manage risk for the GPI program.60 knowledge to manage risk for the GPI program.60
January 2023 DOT&E Report61
A January 2023 report from DOD’s Director, Operational Test and Evaluation (DOT&E)—A January 2023 report from DOD’s Director, Operational Test and Evaluation (DOT&E)—
DOT&E’s annual report for FY2022—states the following regarding the Aegis BMD system: DOT&E’s annual report for FY2022—states the following regarding the Aegis BMD system:
Aegis BMD has demonstrated that it can intercept non-separating, simple-separating, and Aegis BMD has demonstrated that it can intercept non-separating, simple-separating, and
complex-separating ballistic missiles in the midcourse phase of flight with Standard complex-separating ballistic missiles in the midcourse phase of flight with Standard
Missile-3 (SM-3) guided missiles, although flight testing and M&S have not addressed all Missile-3 (SM-3) guided missiles, although flight testing and M&S have not addressed all
expected threat types, ground ranges, and raid sizes. Aegis BMD has also demonstrated a expected threat types, ground ranges, and raid sizes. Aegis BMD has also demonstrated a

~~60 Government Accountability Office, Missile Defense[:] Annual Goals Unmet for Deliveries and Testing, GAO-23-~~
~~106011, May 2023, pp. 34-35.~~
~~61 Director, Operational Test & Evaluation, January 2023, 396 pp.~~
~~Congressional Research Service~~

25

~~link to page 30~~ ~~Navy Aegis Ballistic Missile Defense (BMD) Program~~

capability to intercept select ballistic missiles in the terminal phase of flight with SM-6 capability to intercept select ballistic missiles in the terminal phase of flight with SM-6
guided missiles. However, corrective actions are needed to address failure review board guided missiles. However, corrective actions are needed to address failure review board
findings from the two Sea-Based Terminal Increment 2 flight tests in FY21. All fielded findings from the two Sea-Based Terminal Increment 2 flight tests in FY21. All fielded
Aegis BMD variants have demonstrated sufficient reliability, with operational Aegis BMD variants have demonstrated sufficient reliability, with operational
availabilities that exceed the specification. However, SM-3 Block IIA missile reliability is availabilities that exceed the specification. However, SM-3 Block IIA missile reliability is
not known with a high degree of certainty, due to the relatively small number of live firings not known with a high degree of certainty, due to the relatively small number of live firings
and ground test data collection events to date. The MDA is implementing a process to and ground test data collection events to date. The MDA is implementing a process to
monitor the health and status of deployed SM-3 Block IIA missiles, which will provide monitor the health and status of deployed SM-3 Block IIA missiles, which will provide
additional reliability data for future assessments.... additional reliability data for future assessments....
... In FY22, Aegis BMD, with AN/SPY-1, demonstrated the capability to detect, track, and ... In FY22, Aegis BMD, with AN/SPY-1, demonstrated the capability to detect, track, and
report on resident space objects based on SDA tasking received by C2BMC [Command report on resident space objects based on SDA tasking received by C2BMC [Command
and Control, Battle Management, and Communications] during an at-sea demonstration. and Control, Battle Management, and Communications] during an at-sea demonstration.
The AN/SPY-6(V)1 radar prototype at the Pacific Missile Range Facility continues to track The AN/SPY-6(V)1 radar prototype at the Pacific Missile Range Facility continues to track
all classes of ballistic missiles, as available, during MDS flight tests.62 all classes of ballistic missiles, as available, during MDS flight tests.62
Legislative Activity for FY2024
Summary of Action on FY2024 MDA Funding Request
Table 2 summarizes congressional action on the FY2024 request for MDA procurement and summarizes congressional action on the FY2024 request for MDA procurement and
research and development funding for the Aegis BMD program. research and development funding for the Aegis BMD program.
60 Government Accountability Office, Missile Defense[:] Annual Goals Unmet for Deliveries and Testing, GAO-23-106011, May 2023, pp. 34-35. 61 Director, Operational Test & Evaluation, January 2023, 396 pp. 62 Director, Operational Test & Evaluation, January 2023, pp. 307-308. Congressional Research Service 25 link to page 30 link to page 30 Navy Aegis Ballistic Missile Defense (BMD) Program Table 2. Summary of Congressional Action on FY2024 MDA Funding Request
(In millions of dollars, rounded to nearest tenth; totals may not add due to rounding) (In millions of dollars, rounded to nearest tenth; totals may not add due to rounding)
Authorization
Appropriation

Request
HASC
SASC
Final
HAC
SAC
Final
Procurement
Aegis BMD (line 33) Aegis BMD (line 33)
374.8 374.8
419.8 419.8
374.8 374.8

374.8 374.8 374.8
374.8 374.8

(SM-3 Block IB missile quantity)
(27)
(27)
(27)
(27)
(27)
(27)

Aegis BMD Advance Procurement (line 34) Aegis BMD Advance Procurement (line 34)
0 0
0 0
0 0

0 0 0
0 0

SM-3 Block IIA (line 36) SM-3 Block IIA (line 36)
432.8 432.8
432.8 432.8
432.8 432.8

432.8 432.8 432.8
432.8 432.8

(SM-3 Block IIA missile quantity)
(12)
(12)
(12)
(12)
(12)
(12)

Aegis Ashore Phase III (line 40) Aegis Ashore Phase III (line 40)
2.4 2.4
2.4 2.4
2.4 2.4

2.4 2.4 2.4
2.4 2.4

Aegis BMD hardware and software (line 42) Aegis BMD hardware and software (line 42)
27.8 27.8
27.8 27.8
27.8 27.8

27.8 27.8 27.8
27.8 27.8

Subtotal Procurement
837.8
882.8
837.8
837.8
837.8
837.8

Research, development, test, and evaluation (RDT&E)
Aegis BMD (PE 0603892C) (line 83) Aegis BMD (PE 0603892C) (line 83)
693.7 693.7
709.7 709.7
693.7 693.7

689.7 698.9 698.9
693.7 693.7

Aegis BMD test (PE 0604878C) (line 114) Aegis BMD test (PE 0604878C) (line 114)
193.5 193.5
193.5 193.5
193.5 193.5

188.4 188.4 188.4
184.3 184.3

Land-based SM-3 (PE 0604880C) (line 116) Land-based SM-3 (PE 0604880C) (line 116)
22.2 22.2
22.2 22.2
22.2 22.2

22.2 22.2 22.2
22.2 22.2

Subtotal RDT&E
909.4
925.4
909.4
900.3
909.5
900.2

TOTAL
1,747.2
1,808.2
1,747.2
1,738.1 1,747.3 1,738.0
~~1,747.3~~
~~1,738.0~~

~~62 Director, Operational Test & Evaluation, January 2023, pp. 307-308.~~
~~Congressional Research Service~~

26

~~link to page 30 link to page 30 link to page 30 link to page 30~~ ~~Navy Aegis Ballistic Missile Defense (BMD) Program~~

Source: Table prepared by CRS based on DOD’s original FY2024 budget submission, committee and Table prepared by CRS based on DOD’s original FY2024 budget submission, committee and
conference reports, and explanatory statements on FY2024 National Defense Authorization Act and FY2024 conference reports, and explanatory statements on FY2024 National Defense Authorization Act and FY2024
DOD Appropriations Act. DOD Appropriations Act.
Notes: HASC is House Armed Services Committee; is House Armed Services Committee; SASC is Senate Armed Services Committee; is Senate Armed Services Committee; HAC is is
House Appropriations Committee; House Appropriations Committee; SAC is Senate Appropriations Committee. is Senate Appropriations Committee.
FY2024 National Defense Authorization Act (H.R. 2670/S. 2226)
House
The House Armed Services Committee, in its report (H.Rept. 118-125 of June 30, 2023) on H.R. The House Armed Services Committee, in its report (H.Rept. 118-125 of June 30, 2023) on H.R.
2670, recommended the funding levels shown in the HASC column of2670, recommended the funding levels shown in the HASC column of Table 2.
The recommended increase of $45.0 million for line 33 is for “MDA UPL [Unfunded Priorities The recommended increase of $45.0 million for line 33 is for “MDA UPL [Unfunded Priorities
list]—SM–3 Blk 1B Life Extension.” (Page 467) list]—SM–3 Blk 1B Life Extension.” (Page 467)
The recommended net increase of $16.0 million for line 83 includes a recommended increase of The recommended net increase of $16.0 million for line 83 includes a recommended increase of
$20.0 million for “PAC–3 [Patriot Advanced Capability 3] MSE [Missile Segment $20.0 million for “PAC–3 [Patriot Advanced Capability 3] MSE [Missile Segment
Enhancement]/AEGIS Weapon System Integration” and a recommended reduction of $4.0 Enhancement]/AEGIS Weapon System Integration” and a recommended reduction of $4.0
million for “Program decrease.” (Page 511) million for “Program decrease.” (Page 511)
Section 1667 of H.R. 2670 requires MDA to submit a report to the congressional defense of H.R. 2670 requires MDA to submit a report to the congressional defense
committees on potential enhancements to Aegis Ashore sites in Poland and Romania. committees on potential enhancements to Aegis Ashore sites in Poland and Romania.
Senate
The Senate Armed Services Committee, in its report (S.Rept. 118-58 of July 12, 2023) on S. The Senate Armed Services Committee, in its report (S.Rept. 118-58 of July 12, 2023) on S.
2226, recommended the funding levels shown in the SASC column of2226, recommended the funding levels shown in the SASC column of Table 2.
Congressional Research Service 26 link to page 30 link to page 30 link to page 30 Navy Aegis Ballistic Missile Defense (BMD) Program H.Rept. 118-301 states: Report on potential enhancements to Aegis Ashore sites in Poland and Romania The House bill contained a provision (sec. 1667) that would require the Director of the Missile Defense Agency to provide a report on potential enhancements to the Aegis Ashore missile defense sites in Poland and Romania. The Senate amendment contained no similar provision. The House recedes. The conferees direct that, no later than April 30, 2024, the Director of the Missile Defense Agency shall submit to the congressional defense committees a report on potential enhancements to Aegis Ashore sites in Poland and Romania. This report shall include the following elements: (1) An assessment of the feasibility and advisability of— (a) enhancing associated sensor systems to detect a broader array of missile threats; (b) fielding a mixed fleet of defensive interceptor systems; and (c) physical hardening of the facilities; (2) A funding profile, by year, detailing the complete costs associated with any options assessed under paragraph (1); and (3) Such other information as the Director considers appropriate. This report shall be in unclassified form, but may include a classified annex. (Pages 1318-1319) Conference The conference report (H.Rept. 118-301) on H.R. 2670 recommended the funding levels shown in the authorization final column of Table 2. The recommended reduction of $4.0 million for line 83 is for “Program decrease.” (Page 1486). The recommended reduction of $5.049 million for line 114 is for “Excess growth.” (Page 1488) FY2024 DOD Appropriations Act (H.R. 4365/S. 2587)
House
The House Appropriations Committee, in its report (H.Rept. 118-121 of June 27, 2023) on H.R. The House Appropriations Committee, in its report (H.Rept. 118-121 of June 27, 2023) on H.R.
4365, recommended the funding levels shown in the HAC column of4365, recommended the funding levels shown in the HAC column of Table 2.
The recommended net increase of $5.144 million for line 83 includes a recommended reduction The recommended net increase of $5.144 million for line 83 includes a recommended reduction
of $4.856 million for “Excess growth” and a recommended increase of $10.0 million for of $4.856 million for “Excess growth” and a recommended increase of $10.0 million for
“Program increase—lightweight, radiation-hardened, thermally insensitive sensors.” (Page 243) “Program increase—lightweight, radiation-hardened, thermally insensitive sensors.” (Page 243)
The recommended reduction of $5.049 million for line 114 is for “Excess growth.” (Page 244) The recommended reduction of $5.049 million for line 114 is for “Excess growth.” (Page 244)
Senate
The Senate Appropriations Committee, in its report (S.Rept. 118-81 of July 27, 2023) on S. 2587, The Senate Appropriations Committee, in its report (S.Rept. 118-81 of July 27, 2023) on S. 2587,
recommended the funding levels shown in the SAC column ofrecommended the funding levels shown in the SAC column of Table 2.
The recommended reduction of $9.231 million for line 114 is for “Prior year test adjustments.” The recommended reduction of $9.231 million for line 114 is for “Prior year test adjustments.”
(Page 252) (Page 252)

Congressional Research Service Congressional Research Service

27 27

link to page 32 link to page 32 Navy Aegis Ballistic Missile Defense (BMD) Program

Appendix. Reported Aegis BMD Flight Tests
Table A-1 presents a summary of reported Aegis BMD flight tests since January 2002. In addition presents a summary of reported Aegis BMD flight tests since January 2002. In addition
to the flight tests shown in the table, on February 20, 2008, a BMD-capable Aegis cruiser to the flight tests shown in the table, on February 20, 2008, a BMD-capable Aegis cruiser
operating northwest of Hawaii used a modified version of the Aegis BMD system with the SM-3 operating northwest of Hawaii used a modified version of the Aegis BMD system with the SM-3
missile to shoot down an inoperable U.S. surveillance satellite that was in a deteriorating orbit. missile to shoot down an inoperable U.S. surveillance satellite that was in a deteriorating orbit.
Table A-1. Reported Aegis BMD Flight Tests From January 2002 to the Present
Name of flight
Reported as Date
Country
test of exercise
Ballistic Missile Target
~~Successful~~successful?
Exo-atmospheric (using SM-3 missile)
1/25/02 1/25/02
US US
FM-2 FM-2
Unitary short-range (TTV) Unitary short-range (TTV)
Yes Yes
6/13/02 6/13/02
US US
FM-3 FM-3
Unitary short-range (TTV) Unitary short-range (TTV)
Yes Yes
11/21/02 11/21/02
US US
FM-4 FM-4
Unitary short-range (TTV) Unitary short-range (TTV)
Yes Yes
6/18/03 6/18/03
US US
FM-5 FM-5
Unitary short-range (TTV) Unitary short-range (TTV)
No
12/11/03 12/11/03
US US
FM-6 FM-6
Unitary short-range (TTV) Unitary short-range (TTV)
Yes Yes
2/24/05 2/24/05
US US
FTM 04-1 (FM-7) Unitary short-range (TTV) FTM 04-1 (FM-7) Unitary short-range (TTV)
Yes Yes
11/17/05 11/17/05
US US
FTM 04-2 (FM-8) Separating short-range (MRT) FTM 04-2 (FM-8) Separating short-range (MRT)
Yes Yes
6/22/06 6/22/06
US US
FTM 10 FTM 10
Separating short-range (TTV) Separating short-range (TTV)
Yes Yes
12/7/06 12/7/06
US US
FTM 11 FTM 11
Unitary short-range (TTV) Unitary short-range (TTV)
No
4/26/07 4/26/07
US US
FTM 11 FTM 11
Unitary short-range (ARAV-A) Unitary short-range (ARAV-A)
Yes Yes
Event 4 Event 4
6/22/07 6/22/07
US US
FTM 12 FTM 12
Separating short-range (MRT) Separating short-range (MRT)
Yes Yes
8/31/07 8/31/07
US US
FTM-11a FTM-11a
Classified Classified
Yes Yes
11/6/07 11/6/07
US US
FTM 13 FTM 13
Unitary short-range (ARAV-A) Unitary short-range (ARAV-A)
Yes Yes

Unitary short-range (ARAV-A) Unitary short-range (ARAV-A)
Yes Yes
12/17/07 12/17/07
Japan Japan
JFTM-1 JFTM-1
Separating short-range (MRT) Separating short-range (MRT)
Yes Yes
11/1/08 11/1/08
US US
Pacific Blitz Pacific Blitz
Unitary short-range (ARAV-A) Unitary short-range (ARAV-A)
Yes Yes

Unitary short-range (ARAV-A) Unitary short-range (ARAV-A)
No
11/19/08 11/19/08
Japan Japan
JFTM-2 JFTM-2
Separating short-range (MRT) Separating short-range (MRT)
No
7/30/09 7/30/09
US US
FTM-17 FTM-17
Unitary short-range (ARAV-A) Unitary short-range (ARAV-A)
Yes Yes
10/27/09 10/27/09
Japan Japan
JFTM-3 JFTM-3
Separating short-range (MRT) Separating short-range (MRT)
Yes Yes
10/28/10 10/28/10
Japan Japan
JFTM-4 JFTM-4
Separating short-range (MRT) Separating short-range (MRT)
Yes Yes
4/14/11 4/14/11
US US
FTM-15 FTM-15
Separating intermediate range (LV-2) Separating intermediate range (LV-2)
Yes Yes
9/1/11 9/1/11
US US
FTM-16 E2 FTM-16 E2
Separating short-range (ARAV-B) Separating short-range (ARAV-B)
No
5/9/12 5/9/12
US US
FTM-16 E2a FTM-16 E2a
Unitary short-range (ARAV-A) Unitary short-range (ARAV-A)
Yes Yes
6/26/12 6/26/12
US US
FTM-18 FTM-18
Separating short-range (MRT) Separating short-range (MRT)
Yes Yes
10/25/12 10/25/12
US US
FTI-01 FTI-01
Separating short-range (ARAV-B) Separating short-range (ARAV-B)
No
2/12/13 2/12/13
US US
FTM-20 FTM-20
Separating medium-range (MRBM-T3) Separating medium-range (MRBM-T3)
Yes Yes
5/15/13 5/15/13
US US
FTM-19 FTM-19
Separating short-range (ARAV-C) Separating short-range (ARAV-C)
Yes Yes
Congressional Research Service Congressional Research Service

28 28

link to page 34 link to page 34 link to page 34 link to page 34 link to page 34 link to page 34 Navy Aegis Ballistic Missile Defense (BMD) Program

Name of flight
Reported as Date
Country
test of exercise
Ballistic Missile Target
~~Successful~~successful?
9/10/13 9/10/13
US US
FTO-01 FTO-01
Separating medium-range (eMRBM-T1) Separating medium-range (eMRBM-T1)
Yes Yes
9/18/13 9/18/13
US US
FTM-21 FTM-21
Separating short-range (ARAV-C++) Separating short-range (ARAV-C++)
Yes Yes
10/3/13 10/3/13
US US
FTM-22 FTM-22
Separating medium-range (ARAV-TTO-E) Separating medium-range (ARAV-TTO-E)
Yes Yes
11/6/14 11/6/14
US US
FTM-25 FTM-25
Separating short-range (ARAV-B) Separating short-range (ARAV-B)
Yes Yes
6/25/15 6/25/15
US US
FTO-02 E1 FTO-02 E1
Separating medium-range (IRBM T1) Separating medium-range (IRBM T1)
n n/aa
10/4/15 10/4/15
US US
FTO-02 E2 FTO-02 E2
Separating medium-range (eMRBM) Separating medium-range (eMRBM)
n n/ab
10/20/15 10/20/15
US US
ASD-15 E2 ASD-15 E2
Separating short-range (Terrier Orion) Separating short-range (Terrier Orion)
Yes Yes
11/1/15 11/1/15
US US
FTO-02 E2a FTO-02 E2a
Separating medium-range (eMRBM) Separating medium-range (eMRBM)
No
12/10/15 12/10/15
US (Aegis US (Aegis
FTO02 E1a FTO02 E1a
Separating medium-range (IRBM T1) Separating medium-range (IRBM T1)
Yes Yes
Ashore) Ashore)
2/3/17 2/3/17
US-Japan US-Japan
SFTM-01 SFTM-01
Separating medium-range (MRT) Separating medium-range (MRT)
Yes Yes
6/21/17 6/21/17
US-Japan US-Japan
SFTM-02 SFTM-02
Medium-range target Medium-range target
No
10/15/17 10/15/17
US US
FS17 FS17
Medium-range target Medium-range target
Yes Yes
1/31/18 1/31/18
US (Aegis US (Aegis
FTM-29 FTM-29
Intermediate-range target Intermediate-range target
No
Ashore) Ashore)
9/11/18 9/11/18
Japan Japan
JFTM-05 JFTM-05
Simple separating target Simple separating target
Yes Yes
10/26/18 10/26/18
US US
FTM-45 FTM-45
Medium range target Medium range target
Yes Yes
12/10/18 12/10/18
US (Aegis US (Aegis
FTI-03 FTI-03
Intermediate-range target Intermediate-range target
Yes Yes
Ashore) Ashore)
11/16/20 11/16/20
US US
FTM-44 FTM-44
ICBM target ICBM target
Yes Yes
5/26 and 5/26 and
US- US-
ASD/FS21c ASD/FS21c
Non-separating MRBM target Non-separating MRBM target
Y Yesc
30/2021 30/2021
Netherlands Netherlands
4/9/22f 4/9/22f
US US
FEM-01 FEM-01
Medium range target Medium range target
Outcome not Outcome not
reported reported
8/9/22 8/9/22
US US
Part of Pacific Part of Pacific
ARAV-B SRBM target ARAV-B SRBM target
Yes Yes
Dragon exercise Dragon exercise
11/16/22e 11/16/22e
US-Japan US-Japan
JFTM-07 JFTM-07
Medium-range T4-E target Medium-range T4-E target
Yes Yes
11/18 or 11/18 or
US-Japan US-Japan
JFTM-07 JFTM-07
Short-range target Short-range target
Yes Yes
19/22e 19/22e
ca. 10/25/23 US Vigilant Wyvern/ Two short-range targets Yes FTM-48 Endo-atmospheric (using SM-2 missile Block IV missile and [for MMW E1 and subsequent] SM-6
Dual 1 missile)
5/24/06 5/24/06
US US
Pacific Phoenix Pacific Phoenix
Unitary short-range target (Lance) Unitary short-range target (Lance)
Yes Yes
6/5/08 6/5/08
US US
FTM-14 FTM-14
Unitary short-range target (FMA) Unitary short-range target (FMA)
Yes Yes
3/26/09 3/26/09
US US
Stellar Daggers Stellar Daggers
Unitary short-range target (Lance) Unitary short-range target (Lance)
Yes Yes
7/28/15 7/28/15
US US
MMW E1 MMW E1
Unitary short-range target (Lance) Unitary short-range target (Lance)
Yes Yes
7/29/15 7/29/15
US US
MMW E2 MMW E2
Unitary short-range target (Lance) Unitary short-range target (Lance)
Yes Yes
12/14/16 12/14/16
US US
FTM-27 FTM-27
Unitary short-range target (Lance) Unitary short-range target (Lance)
Yes Yes
8/29/17 8/29/17
US US
FTM-27 E2 FTM-27 E2
Medium-range target (MRBM) Medium-range target (MRBM)
Yes Yes
~~5/29/21~~
US
~~FTM-31~~
~~Medium-range target (MRBM)~~
No
Congressional Research Service Congressional Research Service

29 29

Navy Aegis Ballistic Missile Defense (BMD) Program

Name of flight
Reported as Date
Country
test of exercise
Ballistic Missile Target
~~Successful?~~successful? 5/29/21 US FTM-31 Medium-range target (MRBM) No
7/24/21 7/24/21
US US
FTM-33 FTM-33
Two SRBM targets Two SRBM targets
Yes and Yes and
unconfirmedd
3/30/23 3/30/23
US US
FTM-31 E1a FTM-31 E1a
Medium-Range target (MRBM) Medium-Range target (MRBM)
Yes (2-missile Yes (2-missile
salvo) salvo)
Sources: Table presented in MDA fact sheet, “Aegis Ballistic Missile Defense Testing,” February 2017, accessed Table presented in MDA fact sheet, “Aegis Ballistic Missile Defense Testing,” February 2017, accessed
on May 18, 2022, at https://web.archive.org/web/20170929180757/https:/www.mda.mil/global/documents/pdf/on May 18, 2022, at https://web.archive.org/web/20170929180757/https:/www.mda.mil/global/documents/pdf/
aegis_tests.pdf, and (for flight tests subsequent to February 2017) MDA news releases, Jason Sherman, “U.S. aegis_tests.pdf, and (for flight tests subsequent to February 2017) MDA news releases, Jason Sherman, “U.S.
Intercepted Ballistic Missile Target over Pacific while China Exercised around Taiwan,” Intercepted Ballistic Missile Target over Pacific while China Exercised around Taiwan,” Inside Defense, August 12, , August 12,
2022; and Wyatt Olson, “Missile-Defense Exercise Off Hawaiian Island Includes First Live-Fire Intercept,” 2022; and Wyatt Olson, “Missile-Defense Exercise Off Hawaiian Island Includes First Live-Fire Intercept,” Stars
and Stripes, August 16, 2022. , August 16, 2022.
Notes: TTV is target test vehicle; is target test vehicle; ARAV is Aegis Readiness Assessment Vehicle. In addition to the flight tests is Aegis Readiness Assessment Vehicle. In addition to the flight tests
shown above, there was a successful use of an SM-3 on February 20, 2008, to intercept an inoperative U.S. shown above, there was a successful use of an SM-3 on February 20, 2008, to intercept an inoperative U.S.
satellite—an operation called Burnt Frost. satellite—an operation called Burnt Frost.
a. MDA’s table shows this as a test that did not result in the launch of an SM-3. MDA as of August 3, 2015, a. MDA’s table shows this as a test that did not result in the launch of an SM-3. MDA as of August 3, 2015,
had not issued a news release discussing this event. MDA’s count of 31 successful intercepts in 37 launches had not issued a news release discussing this event. MDA’s count of 31 successful intercepts in 37 launches
through July 29, 2015, does not appear to include this test, suggesting that this was considered a “no test” through July 29, 2015, does not appear to include this test, suggesting that this was considered a “no test”
event—a test in which there was a failure that was not related to the Aegis BMD system or the SM-3 event—a test in which there was a failure that was not related to the Aegis BMD system or the SM-3
interceptor. Press reports state that the test was aborted due to a failure of the target missile. (Andrea interceptor. Press reports state that the test was aborted due to a failure of the target missile. (Andrea
Shalal, “U.S. Skips Aegis Ashore Missile Test After Target Malfunction,” Shalal, “U.S. Skips Aegis Ashore Missile Test After Target Malfunction,” Reuters, June 26, 2015.) MDA’s table , June 26, 2015.) MDA’s table
similarly shows the test of December 7, 2006, as a test that did not result in the launch of an SM-3. MDA similarly shows the test of December 7, 2006, as a test that did not result in the launch of an SM-3. MDA
issued a news release on this test, which stated that an SM-3 was not launched “due to an incorrect system issued a news release on this test, which stated that an SM-3 was not launched “due to an incorrect system
setting aboard the Aegis-class cruiser USS setting aboard the Aegis-class cruiser USS Lake Erie prior to the launch of two interceptor missiles from the prior to the launch of two interceptor missiles from the
ship. The incorrect configuration prevented the fire control system aboard the ship from launching the first ship. The incorrect configuration prevented the fire control system aboard the ship from launching the first
of the two [SM-3] interceptor missiles. Since a primary test objective was a near-simultaneous launch of two of the two [SM-3] interceptor missiles. Since a primary test objective was a near-simultaneous launch of two
missiles against two different targets, the second interceptor missile was intentionally not launched.” MDA missiles against two different targets, the second interceptor missile was intentionally not launched.” MDA
counts the test of December 7, 2006, as an unsuccessful intercept in its count of 31 successful intercepts in counts the test of December 7, 2006, as an unsuccessful intercept in its count of 31 successful intercepts in
37 launches through July 29, 2015. 37 launches through July 29, 2015.
b. MDA’s table shows this as a test that did not result in the launch of an SM-3. MDA as of November 10, b. MDA’s table shows this as a test that did not result in the launch of an SM-3. MDA as of November 10,
2015, had not issued a news release discussing this event. MDA’s count of 32 successful intercepts in 39 2015, had not issued a news release discussing this event. MDA’s count of 32 successful intercepts in 39
launches through November 1, 2015, does not appear to include this test, suggesting that this was launches through November 1, 2015, does not appear to include this test, suggesting that this was
considered a “no test” event—a test in which there was a failure that was not related to the Aegis BMD considered a “no test” event—a test in which there was a failure that was not related to the Aegis BMD
system or the SM-3 interceptor. system or the SM-3 interceptor.
c. ASD/FS21 was an at-sea demonstration that occurred during a multilateral naval exercise called Formidable c. ASD/FS21 was an at-sea demonstration that occurred during a multilateral naval exercise called Formidable
Shield 2021. In the demonstration, a Dutch frigate used its radar to provide early warning track data to a Shield 2021. In the demonstration, a Dutch frigate used its radar to provide early warning track data to a
U.S. Navy destroyer that used the data to calculate a firing solution and launch its interceptor. Some press U.S. Navy destroyer that used the data to calculate a firing solution and launch its interceptor. Some press
reports state that ASD/FS21 involved two successful ballistic missile intercepts, rather than the one shown reports state that ASD/FS21 involved two successful ballistic missile intercepts, rather than the one shown
in the table. in the table.
d. MDA stated that “based on initial observations, one target was successful y intercepted. At this time, we d. MDA stated that “based on initial observations, one target was successful y intercepted. At this time, we
cannot confirm the second target was destroyed.” (“MDA Test Intercepts Target,” MDA News Release 21- cannot confirm the second target was destroyed.” (“MDA Test Intercepts Target,” MDA News Release 21-
NEWS-0012, July 24, 2021.) NEWS-0012, July 24, 2021.)
e. A November 21, 2022, MDA new released stated: “The Japan Maritime Self-Defense Force (JMSDF) and the e. A November 21, 2022, MDA new released stated: “The Japan Maritime Self-Defense Force (JMSDF) and the
United States Missile Defense Agency (MDA) announce the successful completion of a two-week missile United States Missile Defense Agency (MDA) announce the successful completion of a two-week missile
defense event incorporating two live fire exercises.” (Missile Defense Agency, “Japan Missile Defense Flight defense event incorporating two live fire exercises.” (Missile Defense Agency, “Japan Missile Defense Flight
Test Successful,” 22-NEWS-0009, November 21, 2022.) Presss reports stated that two intercept events Test Successful,” 22-NEWS-0009, November 21, 2022.) Presss reports stated that two intercept events
occurred on November 16 and November 18 or 19. (Dzirhan Mahadzir, “Two Japanese Destroyers Score occurred on November 16 and November 18 or 19. (Dzirhan Mahadzir, “Two Japanese Destroyers Score
in Ballistic Missile Defense Test off Hawaii,” in Ballistic Missile Defense Test off Hawaii,” USNI News, November 21, 2022; Rich Abott, “Japanese , November 21, 2022; Rich Abott, “Japanese
Destroyers First Successful y Test SM-3 In Ballistic Missile Defense Test,” Destroyers First Successful y Test SM-3 In Ballistic Missile Defense Test,” Defense Daily, November 22, , November 22,
2022.) 2022.)
f. f.
For a press report about the SM-3 flight test of April 9, 2022, see Jason Sherman, “MDA Acknowledges For a press report about the SM-3 flight test of April 9, 2022, see Jason Sherman, “MDA Acknowledges
Clandestine SM-3 Block IIA Experiment of Classified Capability,” Clandestine SM-3 Block IIA Experiment of Classified Capability,” Inside Defense, January 26, 2023. , January 26, 2023.

Congressional Research Service Congressional Research Service

30 30

Navy Aegis Ballistic Missile Defense (BMD) Program

Author Information

Ronald O'Rourke Ronald O'Rourke

Specialist in Naval Affairs Specialist in Naval Affairs

Disclaimer
This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan
shared staff to congressional committees and Members of Congress. It operates solely at the behest of and shared staff to congressional committees and Members of Congress. It operates solely at the behest of and
under the direction of Congress. Information in a CRS Report should not be relied upon for purposes other under the direction of Congress. Information in a CRS Report should not be relied upon for purposes other
than public understanding of information that has been provided by CRS to Members of Congress in than public understanding of information that has been provided by CRS to Members of Congress in
connection with CRS’s institutional role. CRS Reports, as a work of the United States Government, are not connection with CRS’s institutional role. CRS Reports, as a work of the United States Government, are not
subject to copyright protection in the United States. Any CRS Report may be reproduced and distributed in subject to copyright protection in the United States. Any CRS Report may be reproduced and distributed in
its entirety without permission from CRS. However, as a CRS Report may include copyrighted images or its entirety without permission from CRS. However, as a CRS Report may include copyrighted images or
material from a third party, you may need to obtain the permission of the copyright holder if you wish to material from a third party, you may need to obtain the permission of the copyright holder if you wish to
copy or otherwise use copyrighted material. copy or otherwise use copyrighted material.

Congressional Research Service Congressional Research Service
RL33745 RL33745 · VERSION ~~248~~249 · UPDATED
31 31