Order Code RL33745
Sea-Based Ballistic Missile Defense —
Background and Issues for Congress
April 27, 2007
Specialist in National Defense
Foreign Affairs, Defense, and Trade Division
Sea-Based Ballistic Missile Defense — Background
and Issues for Congress
As part of its effort to develop a global ballistic missile defense (BMD) system,
the Department of Defense (DOD) is modifying 18 Navy cruisers and destroyers for
BMD operations, and has deployed a large BMD radar — the Sea-Based X-Band
Radar (SBX) — on a modified floating oil platform. The eventual role for sea-based
systems in the worldwide U.S. BMD architecture has not been determined. The
overall issue for Congress for this report is: What should be the role of sea-based
systems in U.S. ballistic missile defense, and are DOD’s programs for sea-based
BMD capabilities appropriately structured and funded?
Potential strengths of sea-based BMD systems include the ability to conduct
BMD operations from advantageous locations at sea that are inaccessible to groundbased systems, the ability to operate in forward locations in international waters
without permission from foreign governments, and the ability to readily move to new
maritime locations as needed. Potential limitations of sea-based BMD systems
include possible conflicts with performing other ship missions, higher costs relative
to ground-based systems, and vulnerability to attack when operating in forward
The Aegis BMD system in its current (i.e., Block 2004) configuration is
intended to track ballistic missiles of all ranges, including intercontinental ballistic
missiles (ICBMs), and to intercept shorter-ranged ballistic missiles. The Block 2004
configuration is not intended to intercept ICBMs. Current DOD plans call for
modifying 3 Aegis cruisers and 15 Aegis destroyers with the Aegis BMD capability
by the end of 2009. Future versions of the Aegis BMD system are to include a faster
interceptor designed to intercept certain ICBMs. The Aegis BMD system has
achieved eight successful exo-atmospheric intercepts in 10 test flights. Japan is
acquiring the Aegis BMD system; some other allied navies have expressed an interest
in adding BMD capabilities to their ships.
The Aegis BMD program received $1,122.7 million in FY2007 Missile Defense
Agency (MDA) research and development funds. For FY2008, MDA is requesting
$1,059.1 million in research and development funds for the program. The program
also receives additional Navy funds.
Potential specific issues for Congress regarding sea-based BMD systems include
the role of sea-based BMD systems in the eventual U.S. BMD architecture, whether
DOD’s program to replace the canceled Navy Area Defense (NAD) program for seabased terminal-defense operations is adequate, pacing and funding for Aegis BMD
radar and missile upgrades, and whether the Aegis BMD development approach
offers potential lessons for the ground-based midcourse development program. This
report will be updated as events warrant.
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Rationale for Sea-Based BMD Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Potential Strengths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Potential Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Arms Control Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Aegis BMD Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Midcourse Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Program Origin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Intended Capabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Aegis Ships . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Modification Schedule and Initial Deployments . . . . . . . . . . . . . . . . . . 7
Development, Testing, and Certification . . . . . . . . . . . . . . . . . . . . . . . . 8
Sea-Based Terminal Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
DOD Inspector General Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Government Accountability Office (GAO) Report . . . . . . . . . . . . . . . . . . . 17
Aegis BMD Program Funding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Potential Allied Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Japan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Other Countries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Sea-Based X-Band Radar (SBX) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Technical Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Deployment To Alaska . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
March 2007 Tracking Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Navy To Assume Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Potential Other Uses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Potential Issues for Congress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Sea-Based Systems in Eventual BMD Architecture . . . . . . . . . . . . . . . . . . 26
Replacement for Navy Area Defense (NAD) Program . . . . . . . . . . . . . . . . 27
Aegis Radar Upgrades . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
SM-3 Block II/IIA Missile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Kinetic Energy Interceptor (KEI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
CG(X) Cruiser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Development and Testing of Aegis BMD System . . . . . . . . . . . . . . . . . . . . 31
Potential Allied Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Legislative Activity for FY2008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
List of Tables
Aegis BMD Installation Schedule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
ALI and Aegis BMD Flight Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Aegis BMD Program Funding, FY1995-FY2013 . . . . . . . . . . . . . . . . . 20
Detailed MDA Aegis BMD Program Funding . . . . . . . . . . . . . . . . . . . 21
Sea-Based Ballistic Missile Defense —
Background and Issues for Congress
As part of its effort to develop a global ballistic missile defense (BMD) system,
the Department of Defense (DOD) is modifying 18 Navy cruisers and destroyers for
BMD operations, and has deployed a large BMD radar — the Sea-Based X-Band
Radar (SBX) — on a modified floating oil platform. The eventual role for sea-based
systems in the world-wide U.S. BMD architecture has not been determined.
The overall issue for Congress for this report is: What should be the role of seabased systems in U.S. ballistic missile defense, and are DOD’s programs for seabased BMD capabilities appropriately structured and funded? Decisions that
Congress reaches on this issue could affect U.S. BMD capabilities and funding
requirements; the size, capabilities, and operational patterns of the Navy and the
other services; and the shipbuilding industrial base.
Rationale for Sea-Based BMD Systems
DOD’s overall BMD plan includes ground-based, sea-based, airborne, and
space-based systems, each of which have potential strengths and limitations. DOD
believes that a combination of these systems will provide a more capable BMD
Potential Strengths. Potential strengths of sea-based BMD systems
compared to other BMD systems include the following:
Advantageous locations at sea. Sea-based systems can conduct
BMD operations from locations at sea that are potentially
advantageous for BMD operations but inaccessible to ground-based
Base access and freedom of action. Sea-based systems can be
operated in forward (i.e., overseas) locations in international waters
without need for negotiating base access from other governments,
and without restrictions from foreign governments on how they
might be used.
Visibility. Sea-based systems can operate over the horizon from
observers ashore, making them potentially less visible and less
Mobility. Navy ships with BMD systems can readily move
themselves to respond to changing demands for BMD capabilities or
to evade detection and targeting by enemy forces, and can do so
without placing demands on U.S. airlift assets.
Regarding the first of these potential strengths, there are at least four ways that
a location at sea can be advantageous for U.S. BMD operations:
The location might lie along a ballistic missile’s potential flight path,
which can facilitate tracking and intercepting the attacking missile.
The location might permit a sea-based radar to view a ballistic
missile from a different angle than other U.S. BMD sensors, which
might permit the U.S. BMD system to track the attacking missile
If a potential adversary’s ballistic missile launchers are relatively
close to its coast, then a U.S. Navy ship equipped with BMD
interceptors that is operating relatively close to that coast could
attempt to defend a large down-range territory against potential
attack by ballistic missiles fired from those launchers.1 One to four
Navy ships operating in the Sea of Japan, for example, could attempt
to defend most or all of Japan against theater-range ballistic missiles
(TBMs)2 fired from North Korea.
If a Navy ship were equipped with very fast interceptors (i.e.,
interceptors faster than those the Navy is currently deploying), and
if that ship were deployed to an overseas location relatively close to
enemy ballistic missile launchers, the ship might be able to attempt
to intercept ballistic missiles fired from those launchers during the
missiles’ boost phase of flight — the initial phase, during which the
ballistic missiles’ rocket engines are burning. A ballistic missile in
the boost phase of flight is a relatively large, hot-burning target that
The ship’s potential ability to do this is broadly analogous to how a hand casts a shadow
in a candle-lit room. The closer that the hand (i.e., the Navy ship) is moved to the candle
(the ballistic missile launcher), the larger becomes the hand’s shadow on the far wall (the
down-range area that the ship can help defend against ballistic missile attack). In BMD
parlance, the area in shadow is referred to as the defended footprint.
TBMs include, in ascending order of range, short-range ballistic missiles (SRBMs), which
generally fly up to about 600 kilometers (about 324 nautical miles), medium-range ballistic
missiles (MRBMs), which generally fly up to about 1,300 kilometers (about 702 nm), and
intermediate-range ballistic missiles (IRBMs), which generally fly up to about 5,500
kilometers (about 2,970 nm). Intercontinental ballistic missiles (ICBMS) are longer-ranged
missiles that can fly 10,000 kilometers (about 5,400 nm) or more. Although ICBMs can be
used to attack targets within their own military theater, they are not referred to as TBMs.
might be easier to intercept (in part because the missile is flying
relatively slowly and is readily seen by radar), and the debris from
a missile intercepted during its boost phase might be more likely to
not fall on or near the intended target of the attacking missile.
Potential Limitations. Potential limitations of sea-based BMD systems
compared to other BMD systems include the following:
Conflicts with other ship missions. Using multimission Navy
cruisers and destroyers for BMD operations might reduce their
ability to perform other missions, such as air-defense operations
against aircraft and anti-ship cruise missiles (ASCMs), land-attack
operations, and anti-submarine warfare operations, for four reasons:
— Conducting BMD operations might require a ship to
operate in a location that is unsuitable for performing one or
more other missions.
— Conducting BMD operations may reduce a ship’s ability
to conduct air-defense operations against aircraft and cruise
missiles due to limits on ship radar abilities.
— BMD interceptors occupy ship weapon-launch tubes that
might otherwise be used for air-defense, land-attack, or antisubmarine weapons.
— Launching a BMD interceptor from a submarine might
give away the submarine’s location, which might make it more
difficult for the submarine to perform missions that require
stealthy operations (and potentially make the submarine more
vulnerable to attack).
Costs relative to ground-based systems. A sea-based system
might be more expensive to procure than an equivalent groundbased system due to the potential need to engineer the sea-based
system to resist the corrosive marine environment, resist
electromagnetic interference from other powerful shipboard systems
and meet shipboard safety requirements, or fit into a limited space
aboard ship. A BMD system on a ship or floating platform that is
dedicated to BMD operations might be more expensive to operate
and support than an equivalent ground-based system due to the
maintenance costs associated with operating the ship or platform in
the marine environment and the need for a crew of some size to
operate the ship or platform.
Ship quantities for forward deployments. Maintaining a standing
presence of a Navy BMD ship in a location where other Navy
missions do not require such a deployment, and where there is no
nearby U.S. home port, can require a total commitment of several
Navy ships, due to the mathematics of maintaining Navy ship
Vulnerability to attack. A sea-based BMD system operating in a
forward location might be more vulnerable to enemy attack than a
ground-based system, particularly a ground-based system located in
a less-forward location. Defending a sea-based system against
potential attack could require the presence of additional Navy ships
or other forces.
Rough waters. Very rough waters might inhibit a crew’s ability to
operate a ship’s systems, including its BMD systems, potentially
creating occasional gaps in BMD coverage.
Arms Control Considerations
No arms control treaty currently in force limits sea-based BMD systems. 4
Aegis BMD Program5
The Aegis Ballistic Missile Defense (Aegis BMD) program is DOD’s primary
sea-based BMD program. The program includes an Aegis BMD midcourse program
and a sea-based terminal program. Each of these is discussed below.
Program Origin. The Aegis BMD midcourse program was created by the
Missile Defense Agency (MDA) in 2002. Earlier names for the program include the
Sea-Based Midcourse program, the Navy Theater Wide Defense program, and the
For more on the mathematics of Navy ship forward deployments, see CRS Report
RS21338, Navy Ship Deployments: New Approaches — Background and Issues for
Congress, by Ronald O’Rourke.
The U.S.-Soviet Anti-Ballistic Missile (ABM) Treaty, which was in force from 1972 until
the United States withdrew from the treaty in 2002, prohibited sea-based defenses against
strategic (i.e., long-range) ballistic missiles. Article V of the treaty states in part: “Each
Party undertakes not to develop, test, or deploy ABM systems or components which are
sea-based, air-based, space-based, or mobile land-based.” Article II defines an ABM system
as “a system to counter strategic ballistic missiles or their elements in flight trajectory....”
For more on the ABM Treaty, see CRS Report RL30033, Arms Control and
Nonproliferation Activities: A Catalog of Recent Events, by Amy F. Woolf, coordinator, et
al. The United States withdrew from the ABM Treaty in 2002, according to the treaty’s
procedures for doing so. For a discussion, see CRS Report RS21088, Withdrawal from the
ABM Treaty: Legal Considerations, by David M. Ackerman.
Unless otherwise stated, information on the Aegis BMD program is taken from an April
2006 Missile Defense Agency (MDA) briefing on the Aegis BMD program — “Aegis
Ballistic Missile Defense, Aegis BMD Update and Plans, Briefing to the Future Naval Plans
& Requirements Conference,” Scott Perry, Aegis BMD [Program Office], April 26, 2006,
Sea-Based Upper Tier program. The program is the successor to earlier sea-based
BMD development efforts dating back to the early 1990s.6
The Aegis BMD program office is an MDA directorate that reports directly to
the director of MDA. MDA provides direction, funding, and guidance to the Aegis
BMD program office and is the acquisition executive for the program. To execute
the program, the Aegis BMD program office was established as a Naval Sea Systems
Command (NAVSEA) field activity. NAVSEA provides administrative support
(e.g., contracting, comptroller, and security) to the Aegis BMD program office.
Intended Capabilities. The Aegis BMD system in its current configuration
(called the Block 2004 configuration; see discussion below) is designed to:
detect and track ballistic missiles of any range, including ICBMs,
intercept short-, and medium-range ballistic missiles (SRBMs and
MRBMs above the atmosphere (i.e., exo-atmospherically) during
their midcourse phase of flight.
When tracking ICBMs, Aegis BMD ships are to act as sensor platforms providing
fire-control-quality tracking data to the overall U.S. BMD architecture.
The Aegis BMD system in its current configuration is not designed to:
intercept intercontinental ballistic missiles (ICBMs) or
intercept ballistic missiles inside the atmosphere, during either their
initial boost phase of flight or their final (terminal) phase of flight.
In contrast to the current configuration of the Aegis BMD system, the groundbased midcourse BMD program, with interceptors based in Alaska and California,
is designed to intercept ICBMs in the midcourse phase of flight. Discussions
comparing the current configuration of the Aegis BMD system and the ground-based
midcourse program have not always noted this basic difference in the kinds of
ballistic missiles they are intended to intercept.
The Aegis BMD program is the successor to the Aegis LEAP Intercept (ALI) Flight
Demonstration Project (FDP), which in turn was preceded by the Terrier Lightweight
Exo-Atmospheric Projectile (LEAP) Project, an effort that began in the early 1990s. Terrier
is an older Navy SAM replaced in fleet use by the Standard Missile. Although succeeded
by the Standard Missile in fleet use, the Navy continued to use the Terrier missile for
development and testing.
As mentioned in an earlier footnote (see section on arms control considerations), the ABM
Treaty, which was in force until 2002, prohibited sea-based defenses against strategic (i.e.,
long-range) ballistic missiles. Navy BMD development activities that took place prior to
2002 were permissible under the ABM treaty because they were not aimed at developing
technologies for countering long-range ballistic missiles.
Aegis Ships. The Aegis BMD system builds on the capabilities of the Navy’s
Aegis ship combat system, which was originally developed for defending ships
against aircraft, anti-ship cruise missiles (ASCMs), surface threats, and subsurface
threats.7 The Aegis system was first deployed by the Navy in 1983, and has been
updated several times since. The part of the Aegis combat system for countering
aircraft and ASCMs is the called the Aegis Weapon System. Key components of the
Aegis Weapon System relevant to this discussion include the following:
the SPY-1 radar — a powerful, phased-array, multifunction radar
that is designed to detect and track multiple targets in flight, and to
provide midcourse guidance to interceptor missiles;
a suite of computers running the Aegis fire control and battlemanagement computer program; and
the Standard Missile (SM) — the Navy’s longer-ranged surface-toair missile (SAM), so called because it was first developed many
years ago as a common, or standard, replacement for a variety of
older Navy SAMs.8
The version of the Standard Missile currently used for air-defense operations is
called the SM-2 Block IV, meaning the fourth upgrade to the second major version
of the Standard Missile. The Navy is developing a new version of the Standard
Missile for future air-defense operations called the SM-6 Extended Range Active
Missile (SM-6 ERAM).
U.S. Navy ships equipped with the Aegis system include Ticonderoga (CG-47)
class cruisers and Arleigh Burke (DDG-51) class destroyers. A total of 27 CG-47s
were procured for the Navy between FY1978 and FY1988; the ships entered service
between 1983 and 1994. The first five, which were built to an earlier technical
standard, were judged by the Navy to be too expensive to modernize and were
removed from service in 2004-2005. The Navy currently plans to keep the remaining
22 ships in service to age 35.
A total of 62 DDG-51s were procured for the Navy between FY1985 and
FY2005; the first entered service in 1991 and the 62nd is scheduled to enter service
in late 2010 or early 2011. The Navy currently plans to keep them in service to age
Between 2010/2011, when the 62nd DDG-51 enters service, and 2021, when the
first of the 22 remaining CG-47s reaches age 35, the Navy plans to maintain a force
of 84 Aegis ships — 22 cruisers and 62 destroyers.
The Aegis system is named after the mythological shield carried by Zeus.
For more on the Aegis system and its principal components as originally deployed, see
CRS Report 84-180 F, The Aegis Anti-Air Warfare System: Its Principal Components, Its
Installation on the CG-47 and DDG-51 Class Ships, and its Effectiveness, by Ronald
O’Rourke. (October 24, 1984) This report is out of print and is available directly from the
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 (the first foreign buyer, with 4 destroyers in service and 2 more
under construction), South Korea (3 destroyers under construction or planned),
Australia (3 destroyers planned), Spain (4 frigates in service and 1 or 2 more
planned), and Norway (1 frigate in service and 4 more under construction or
planned).9 The Norwegian frigates 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.
Modification Schedule and Initial Deployments. Modifying an Aegis
ship for BMD operations involves making two principal changes:
changing the Aegis computer program to permit the SPY-1 radar to
detect and track high-flying ballistic missiles; and
arming the ship with a BMD version of the Standard Missile called
the SM-3 Block 1A.
A ship with the first modification is referred to as having a long-range search
and track (LRS&T) capability. A ship with both modifications is referred to as an
engage-capable ship. Modifying each ship reportedly takes about six weeks and costs
about $10.5 million.10
The SM-3 Block IA is equipped with a kinetic (i.e., non-explosive) warhead
designed to destroy a ballistic missile’s warhead by colliding with it outside the
atmosphere, during the enemy missile’s midcourse phase of flight. It is intended to
intercept SRBMs and MRBMs. An improved version, the Block IB, is to offer some
capability for intercepting intermediate-range ballistic missiles (IRBMs). The Block
IA and IB do not fly fast enough to offer a substantial capability for intercepting
A faster-flying version of the SM-3, called the Block II/IIA, is now being
developed (see discussion below). The Block II/IIA version is intended to give Aegis
BMD ships a capability for intercepting certain ICBMs.
Current DOD plans call for modifying 18 U.S. Aegis ships — 3 cruisers and 15
destroyers — with the Aegis BMD capability. Table 1 shows the planned
installation schedule as of October 2006. Under this schedule, some of the 18 ships
will be modified in two steps, with the LRS&T capability being added first, and the
Source: Jane’s Fighting Ships 2006-2007. Numbers of ships are planned eventual totals.
Jack Dorsey, “Navy On Front Line Of Missile Defense,” Norfolk Virginian-Pilot, October
Longer-range ballistic missiles generally fly faster than shorter-range ballistic missiles.
Consequently, intercepting a longer-range missile generally requires a faster-flying
interceptor than is required for intercepting a shorter-range ballistic missile. The SM-3
Block IA and 1B fly fast enough to intercept TBMs, but not fast enough to provide an
effective capability for intercepting ICBMs.
SM-3 missile being added at a later point. Thus, in Table 1, some ships shown as
LRS&T ships in earlier years migrate to the engage-capable category in later years.
As can be seen in the table, the schedule calls for the Navy to have 10 LRS&T ships
plus 6 engage-capable ships by the end of calender 2006 — with all 16 ships
reportedly to be based in the Pacific Fleet, at least for the time being, according to
one report12 — and 18 engage-capable ships by the end of calendar 2009.
Table 1. Aegis BMD Installation Schedule
(as of October 4, 2006)
Cumulative total by end of calendar year
Total LRS&T Engage-capable ships
Source: U.S. Navy data provided to CRS by Navy Office of Legislative Affairs, October
a. Emergency (i.e., preliminary) engage capability.
Initial Deployments. LRS&T Aegis destroyers began operating in September
2004. Engage-capable Aegis cruisers began operating in September 2005.13
Development, Testing, and Certification. B l o c k De v e l o p m e n t
Strategy. Consistent with the approach used for other parts of DOD’s BMD
acquisition effort, the Aegis BMD system is being developed and deployed in a series
of increasingly capable versions, or blocks, that are named after their approximate
anticipated years of deployment:
The current Block 2004 version includes the SM-3 Block IA missile
and a version of the Aegis computer program called Aegis BMD 3.6,
which allows the ship to perform BMD operations and other warfare
operations (such as air defense) at the same time. (The previous 3.0
Jack Dorsey, “Navy On Front Line Of Missile Defense,” Norfolk Virginian-Pilot, October
The engage-capable cruisers conducted their first operations with an emergency (i.e.,
preliminary) version of the engagement capability.
version of the computer program did not permit this.)14 The Block
2004 version is intended to counter SRBMs and MRBMs.
The Block 2006/2008 version is to include various improvements,
including the Block IB version of the SM-3 and the Aegis BMD
signal processor (Aegis BSP) — a radar signal and data processor
that improves the SPY-1 's ballistic missile target-discrimination
performance. The improvements are intended to, among other
things, give the system a limited ability to intercept IRBMs.
The Block 2010/2012/2014 version is to include further
improvements, including the Block II version of the SM-3 around
2013, and the Block IIA version in 2015. The improvements are
intended to, among other things, give the system some ability to
counter ICBMs. This version will also incorporate changes intended
to make the system suitable for broader international ship
Flight Tests. From January 2002 through April 2007, the Aegis BMD system
has achieved eight successful exo-atmospheric intercepts in 10 flight tests.
Another CRS report, based on historical flight test data provided by MDA to
CRS in June 2005, summarizes early sea-based BMD tests as follows:
The Navy developed its own indigenous LEAP program, which flight tested
from 1992-1995. Three non-intercept flight tests achieved all primary and
secondary objectives. Of the five planned intercept tests, only the second was
considered a successful intercept, however. Failures were due to various
hardware, software, and launch problems. Even so, the Navy determined that it
achieved about 82% of its primary objectives (18 of 22) and all of its secondary
objectives in these tests.15
Regarding the Aegis BMD program’s development approach, the Aegis BMD
program office stated:
We have an expression in the Navy and the Aegis BMD program, “test a little,
learn a lot.” Test more and more and more.... More importantly, the Navy has
chosen to work with the Test and Evaluation community to get the most
operationally relevant scenarios we can. The [engage-capable Aegis cruiser]
USS Lake Erie, on our last few shots, was on a simulated patrol mission. It had
a window of vulnerability — read hours — that they could launch. That was all
the pre-alert they had, with the exception that the captain was notified of that
launch time for safety. Only the ships’ crews man the consoles; there are no
For further discussion of the multimission capability of the 3.6 program see Christopher
P. Cavas, “U.S. Warships To Get Missile Defense Upgrades,” Defense News, October 9,
CRS Report RL33240, Kinetic Energy Kill for Ballistic Missile Defense: A Status
Overview, by Steven A. Hildreth.
technicians there from outside to help the crew. The forward deployed [BMDequipped Aegis] ships are operating with this capability.16
MDA similarly stated that:
The test program for Aegis BMD has focused on the philosophy of “test a
little, learn a lot” since its inception in the early 1990 's with the TERRIER
Lightweight Exo-Atmospheric Projectile (LEAP) Project. TERRIER LEAP
included four flight tests between 1992 and 1995, and was successful in
demonstrating that LEAP technology could be integrated into a sea-based tactical
missile for exoatmospheric ballistic missile defense.
The lessons learned from TERRIER LEAP evolved into the Aegis LEAP
Intercept (ALI) Flight Demonstration Project (FDP), the goal of which was to
utilize the Aegis Weapons System and Standard Missile 3 (SM-3) to hit a
ballistic missile in the exoatmosphere. The ALI test objectives were achieved
with two successful descent phase intercepts of a ballistic missile during Flight
Mission 2 (FM-2) and FM-3 in January 2002 and June 2002 respectively firing
an SM-3 from the [Aegis cruiser] USS LAKE ERIE.
The transition of ALI to an Aegis BMD capability commenced with FM-4
in November of 2002 with USS LAKE ERIE, executing the first successful
ascent phase intercept of a short range ballistic missile (SRBM) by the Aegis
Table 2 below summarizes seven ALI and Aegis BMD flight tests (called FTM2 through FTM-8, with the FTM standing for “flight test mission18) conducted
between January 2002 and November 2005. As shown in the table, 6 of the 7 tests
resulted in successful intercepts.
A. Brad Hicks, Aegis Ballistic Missile Defense (BMD) System. Washington, George C.
Marshall Institute, 2005(?). (Washington Roundtable on Science & Public Policy,
December 19, 2005) p. 13.
“Aegis Ballistic Missile Defense,” MDA fact sheet, January 30, 2004.
In some presentations, the flight tests are referred to as FM-2, etc., without the “T.”
Table 2. ALI and Aegis BMD Flight Tests
Source: “Aegis Ballistic Missile Defense, Aegis BMD Update and Plans,” Briefing to the Future
Naval Plans & Requirements Conference, Scott Perry, Aegis BMD [Program], April 26, 2006, slide
* Aegis ship to Aegis ship and external sensor to Aegis ship.
On June 22, 2006, an eighth Aegis BMD flight test called FTM-10 resulted in
a seventh successful exo-atmospheric intercept in eight attempts. This was the first
test to use the Aegis 3.6 computer program.19
The ninth Aegis BMD flight test, on December 7, 2006, was not successful, and
was the first unsuccessful flight test since June 2003. MDA states that the ninth test,
For additional information on this test, see Missile Defense Agency, “Missile Defense
Test Results in Successful ‘Hit To Kill’ Intercept,”June 22, 2006 (06-NEWS-0018); the
Johns Hopkins University Applied Physics Laboratory press release, “Ballistic Missile
Defense Flight Test a Success,” June 23, 2006, the Lockheed Martin press release, “Aegis
Ballistic Missile Defense Weapon System Guides Missiles to Seventh Successful Target
Intercept,” June 22, 2006; Zachary M. Peterson, “Navy And Missile Defense Agency
Intercept Separating Target,” Inside the Navy, June 26, 2006; and “Take Two: Missile
Defense Test A Success,” NavyTimes.com, June 23, 2006.
was not completed due to an incorrect system setting aboard the Aegis-class
cruiser USS Lake Erie 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 of the two 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.
The planned test was to involve the launch of a Standard Missile 3 against
a ballistic missile target and a Standard Missile 2 against a surrogate aircraft
target. The ballistic missile target was launched from the Pacific Missile Range
Facility, Kauai, Hawaii and the aircraft target was launched from a Navy aircraft.
The USS Lake Erie (CG 70), USS Hopper (DDG 70) and the Royal Netherlands
Navy frigate TROMP were all successful in detecting and tracking their
respective targets. Both targets fell into the ocean as planned.
After a thorough review, the Missile Defense Agency and the U.S. Navy
will determine a new test date.20
A news article about the test stated:
“You can say it’s seven of nine, rather than eight of nine,” Missile Defense
Agency spokesman Chris Taylor said of the second failure in tests of the system
by the agency and the Navy....
The drill was planned to demonstrate the Navy’s ability to knock down two
incoming missiles at once from the same ship.
“In a real world situation it is possible, maybe even probable, that in
addition to engaging a ballistic missile threat that was launched, you may be
engaging a surface action,” said Joe Rappisi before the test. He is director for the
Aegis Ballistic Missile Defense system at Lockheed Martin, the primary
contractor for the program.
The test would have marked the first time a ship has shot down one target
in space and another target in the air at the same time.
The test presented a greater challenge to the ship’s crew and the ballistic
missile defense system than previous tests, Rappisi said. The multiple target
scenario is also closer to what sailors might actually face in battle.
The U.S. Pacific Fleet has been gradually installing missile surveillance and
tracking technology on many of its destroyers and cruisers amid concerns about
North Korea’s long-range missile program.
It is also installing interceptor missiles on many of its ships, even as the
technology to track and shoot down incoming missiles is being developed and
The Royal Netherlands Navy joined the tracking and monitoring off Kauai
to see how its equipment works. The Dutch presence marked the first time a
Untitled Missile Defense Agency “For Your Information” statement dated December 7,
European ally has sent one of its vessels to participate in a U.S. ballistic missile
A subsequent news article stated that:
the test abort of the Aegis Ballistic Missile Defense system Dec. 7 resulted from
human error, [MDA Director USAF Lt. Gen. Henry] Obering says.... Both the
ballistic missile and aircraft targets launched as planned, but the first interceptor
failed to fire because an operator had selected an incorrect setting for the test.
Officials then aborted before the second could boost.
Aegis missile defense system tests are at a standstill until officials are able to
identify an appropriate ballistic missile target. The one used Dec. 7 was the last
of its kind, Obering says, leaving them empty handed in the near future.22
Another article stated:
Philip Coyle, a former head of the Pentagon’s testing directorate, gives the
Navy credit for “discipline and successes so far” in its sea-based ballistic missile
defense testing program. Coyle is now a senior adviser at the Center for Defense
“The U.S. Navy has an enviable track record of successful flight intercept
tests, and is making the most of its current, limited Aegis missile defense
capabilities in these tests,” Coyle told [Inside the Navy] Dec. 7.
“Difficulties such as those that delayed the latest flight intercept attempt
illustrate the complexity of the system, and how everything must be carefully
orchestrated to achieve success,” Coyle added. “Nevertheless, this particular
setback won’t take the Navy long to correct.”23
The tenth Aegis BMD flight test, conducted on April 26, 2007, was successful.
MDA states that the test
involved the simultaneous engagements of a ballistic missile “unitary” target
(meaning that the target warhead and booster remain attached) and a surrogate
hostile air target....
The test demonstrated the [Aegis ship’s] ability to engage a ballistic missile
threat and defend itself from attack at the same time. The test also demonstrated
the effectiveness of engineering, manufacturing, and mission assurance changes
in the solid divert and attitude control system (SDACS) in the kinetic kill
David Briscoe, “Test Interceptor Missile Fails To Launch,” NavyTimes.com, December
Amy Butler, “GMD Trial Delayed Until Spring; Aegis Failure Human Error,” Aerospace
Daily & Defense Report, December 19, 2006.
Zachary M. Peterson, “Sea-Based Missile Defense Test Fails Due To ‘Incorrect
Configuration,’” Inside the Navy, December 11, 2006.
weapon. This was the first flight test of all the SM-3 Block IA’s upgrades,
previously demonstrated in ground tests.24
A press report on the test stated that the hostile air target was an anti-ship cruise
missile. The article stated that the scenario for the test
called for the [Aegis ship] to come under attack from a cruise missile fired by an
enemy plane.... A Navy plane fired the cruise missile target used in the test.25
Certification. On September 11, 2006, the Navy and MDA certified the
version of the Aegis BMD system using the Aegis BMD 3.6 computer program for
SM-3 Block II/IIA Missile (Cooperative Program With Japan). Under
a memorandum of agreement signed in 1999, the United States and Japan have
cooperated in researching technologies for the Block II/IIA version of the SM-3. The
cooperative research has focused on risk reduction for four parts of the missile: the
sensor, an advanced kinetic warhead, the second-stage propulsion, and a lightweight
In contrast to the Block IA/1B version of the SM-3, which has a 21-inchdiameter booster stage but is 13.5 inches in diameter along the remainder of its
length, the Block II/IIA version would have a 21-inch diameter along its entire
length. The increase in diameter to a uniform 21 inches is to give the missile a
burnout velocity (a maximum velocity, reached at the time the propulsion stack burns
out) that is 45% to 60% greater than that of the Block IA/IB version.27 The Block IIA
version would also include an improved kinetic warhead.28 MDA states that the
Missile Defense Agency, “Successful Sea-Based Missile Defense ‘Hit to Kill’ Intercept,”
April 26, 2007 (07-NEWS-0032).
Audrey McAvoy, “Aegis Missile Test Successful,” NavyTimes.com, April 27, 2007.
See Missile Defense Agency, “Aegis Ballistic Missile Defense Weapon System Gains
Fleet Certification,” September 1, 2006 (06-FYI-0082); and Lockheed Martin, “Aegis
Ballistic Missile Defense Weapon System Gains Fleet Certification,” September 11, 2006.
The 13.5-inch version has a reported burnout velocity of 3.0 to 3.5 kilometers per second
(kps). See, for example, J. D. Marshall, The Future Of Aegis Ballistic Missile Defense,
point paper dated October 15, 2004, available at [http://www.marshall.org/
pdf/materials/259.pdf]; “STANDARD Missile-3 Destroyers a Ballistic Missile Target in
Test of Sea-based Missile Defense System,” Raytheon news release circa January 26, 2002,
a va i l a b l e o n t h e Int e r n e t a t [ h t t p : / / www. p r n e ws wire.com/cgi-bi n /
655926&EDATE=Jan+26,+2002]; and Hans Mark, “A White Paper on the Defense Against
Ballistic Missiles,” The Bridge, summer 2001, pp. 17-26, available on the Internet at
$FILE/BrSum01.pdf?OpenElement]. See also the section on “Sea-Based Midcourse” in
CRS Report RL31111, Missile Defense: The Current Debate, coordinated by Steven A.
Source for information on SM-3: Missile Defense Agency, “Aegis Ballistic Missile
Block II/IIA version could “engage many [ballistic missile] targets that would
outpace, fly over, or be beyond the engagement range” of earlier versions of the SM3, and that
the net result, when coupled with enhanced discrimination capability, is more
types and ranges of engageable [ballistic missile] targets; with greater probability
of kill, and a large increase in defended “footprint” or geography predicted....
The SM-3 Blk II/IIA missile with it[s] full 21-inch propulsion stack provides the
necessary fly out acceleration to engage IRBM and certain ICBM threats.29
MDA estimates that the Block II version of the missile could enter service
around 2013, and the Block IIA version in 2015.
Sea-Based Terminal Program
In addition to the midcourse program described above, which is intended to
intercept ballistic missiles outside the atmosphere, during the midcourse phase of
flight, the Aegis BMD program includes a second effort, called the sea-based
terminal capability, to develop a complementary sea-based capability for intercepting
TBMs in the final, or descent, phase of flight, after the missiles reentered the
atmosphere, so as provide local-area defense of U.S. ships as well as friendly forces,
ports, airfields, and other critical assets ashore. The sea-based terminal effort is the
successor to an earlier effort to achieve such a capability that was called the Navy
Area Defense (NAD) program or Navy Area TBMD (Theater BMD) program, and
before that, the Sea-Based Terminal or Navy Lower Tier program.
The NAD system was to have been deployed on Navy Aegis ships. The
program involved modifying the SM-2 Block IV air-defense missile. The missile,
as modified, was called the Block IVA version. The system was designed to
intercept descending missiles endo-atmospherically (i.e., within the atmosphere) and
destroy them with the Block IVA missile’s blast-fragmentation warhead.
In December 2001, DOD announced that it had canceled the NAD program. In
announcing its decision, DOD cited poor performance, significant cost overruns, and
substantial development delays. DOD stated that the program’s unit acquisition and
unit procurement costs had risen 57% and 65%, respectively.30
Defense SM-3 Block IIA (21-Inch) Missile Plan (U), August 2005,” a 9-page point paper
provided by MDA to CRS, August 24, 2005.
“Aegis Ballistic Missile Defense SM-3 Block IIA (21-Inch) Missile Plan (U), August
2005,” op. cit, pp. 3-4.
Acquisition cost is the sum of procurement cost plus research, development, test and
evaluation (RDT&E) cost. In announcing the cancellation, DOD cited the Nunn-McCurdy
provision, a defense acquisition law enacted in 1981. Under the provision as it existed in
2001, a major defense acquisition program experienced what is called a Nunn-McCurdy unit
cost breach when its projected unit cost increased by at least 15%. If the increase reached
25%, the Secretary of Defense, to permit the program to continue, must certify that the
Following cancellation of the NAD program, DOD officials stated that the
requirement for a sea-based terminal BMD system remained intact. This led some
observers to believe that a replacement for the NAD program might be initiated. In
May 2002, however, DOD announced that instead of starting a replacement program,
MDA had instead decided on a two-part strategy to (1) modify the SM-3 missile to
intercept ballistic missiles at somewhat lower altitudes, and (2) modify the fuzes on
the Navy’s inventory of about 100 SM-2 Block IV air defense missiles so that these
missiles can cover some of the remaining portion of the sea-based terminal defense
requirement. The modified Block IV missile uses a blast-fragmentation warhead
similar in concept to that used in the Israeli Arrow BMD interceptor. DOD officials
said the two modified missiles could together provide much (but not all) of the
capability that was to have been provided by the Block IVA missile. One aim of the
modification strategy, DOD officials suggested, was to avoid the added costs to the
BMD program of starting a replacement sea-based terminal defense program.31
MDA stated in 2006 that:
There is currently no sea-based terminal ballistic missile defense capability.
The Navy Area [Defense] Theater Ballistic Missile Defense (TBMD) Program,
had been under development, but was terminated in December 2001. In ballistic
missile defense, the modified Aegis Weapon System, with a modified SM-2
Block IV missile provides a near term, limited emergency capability against a
very specific segment of the ballistic missile threat. The Navy and MDA
consider it vital to develop a more robust capability for terminal ballistic missile
defense of the joint sea base and friendly force embarkation points ashore.32
program is essential to national security, that there are no alternatives to the program that
would provide equal or greater military capability at less cost, that new estimates of the
program’s unit acquisition cost or unit procurement cost appear reasonable, and that the
management structure for the program is adequate to control the program’s unit acquisition
or unit procurement cost.
Edward C. “Pete” Aldridge, the Under Secretary of Defense for Acquisition, Technology
and Logistics — the Pentagon’s chief acquisition executive — concluded, after examining
the NAD program, that he could not recommend to Secretary of Defense Donald Rumsfeld
that he make such a certification. Rumsfeld accepted Aldridge’s recommendation and
declined to issue the certification, triggering the program’s cancellation. This was the first
defense acquisition program that DOD officials could recall having been canceled as a result
of a decision to not certify under a Nunn-McCurdy unit cost breach. (“Navy Area Missile
Defense Program Cancelled,” Department of Defense News Release No. 637-01, December
14, 2001; James Dao, “Navy Missile Defense Plan Is Canceled By the Pentagon,” New York
Times, December 16, 2001; Gopal Ratnam, “Raytheon Chief Asks DOD To Revive Navy
Program,” Defense News, January 14-20, 2002: 10.)
Zachary M. Peterson, “Navy To Field Terminal Pahse, Sea-Based Missile Defense
Capability,” Inside the Navy, June 5, 2006; Gopal Ratnam, “U.S. Studies New Solution To
Naval Missile Defense,” Defense News, May 13-19, 2002: 4; Randy Woods, “DOD Scraps
Navy Area Requirements, Will Expand Midcourse System,” Inside the Navy, May 6, 2002.
Missile Defense Agency, “First at-Sea Demonstration of Sea-Based Terminal Capability
Successfully Completed,” May 24, 2006 (06-FYI-0079).
MDA’s FY2008 budget submission for the Aegis BMD program divides the
sea-based terminal program into a near-term (Block 2008) capability and a far-term
(Block 2014) capability. The Block 2008 capability includes the fuze-modified SM-2
Block IV and is to provide a near-term sea-based terminal capability against a finite
set of SRBMs. The Navy (not MDA) is funding the modification of 100 SM-2 Block
IV missiles. This capability is scheduled to enter service in FY2009. MDA states
that the Block 2014 capability is envisioned as including a new type of missile, the
design of which is not yet determined, that is to provide a more capable and robust
sea-based terminal capability.
A modified Block SM-2 IV missile successfully intercepted a target ballistic
missile inside the atmosphere, during the terminal phase of flight, in a test conducted
on May 24, 2006.33
DOD Inspector General Report
A March 2006 DOD Inspector General Report on system engineering for DOD’s
overall missile effort stated:
Although the Aegis BMD element manager (the element manager) followed
many of the systems engineering processes described in the Defense Acquisition
Guidebook, she had not completed several systems engineering documents and
processes that are important to transition the Aegis BMD Element (the element)
capabilities for Block 04 to the Navy.34
Government Accountability Office (GAO) Report
A March 2007 Government Accountability Office (GAO) report assessing the
status of selected weapon programs stated of the Aegis BMD program:
According to program officials, the Block 1A missile being fielded during
2006-2007 has mature technologies and a stable design. However, we believe
that two critical technologies are less mature because full functionality of these
two capabilities of the new missile has not been demonstrated in a realistic
environment. If events occur that require the new capability, program officials
believe the upgrades will perform as expected. Even without them, officials
noted that the missile provides a credible defense against the Block 2004 threat
See Missile Defense Agency, “First at-Sea Demonstration of Sea-Based Terminal
Capability Successfully Completed,” May 24, 2006 (06-FYI-0079); Gregg K. Kakesako,
“Missile Defense System Makes History,” Honolulu Star-Bulletin, May 25, 2006; Audrey
McAvoy, “Ship Shoots Down Test Missile For The First Time,” NavyTimes.com, May 25,
2006; “Navy, MDA Announce First Terminal Sea-Based Intercept,” Aerospace Daily &
Defense Report, May 26, 2006; Zachary M. Peterson, “Navy Conducts First Sea-Based
Terminal Phase Missile Defense Test,” Inside the Navy, May 29, 2006; and Jeremy Singer,
“Sea-Based Terminal May Boost U.S. Missile Defense Capability,” Space News
(www.space.com), June 12, 2006.
Department of Defense, Office of Inspector General, Acquisition: System Engineering
Planning for the Ballistic Missile Defense System (D-2006-060), March 2, 2006 (redacted
version), p. 9. The report elaborates on the situation in detail on pages 9-16.
set and some of the Block 2006 threat set. All drawings have been released to
manufacturing. The program is not collecting statistical data on its production
process of the Block 1A missile but is using other means to gauge production
Program officials believe that all three technologies critical to the SM-3
Block 1A missile are mature. However, we believe that two of these critical
technologies are less mature. The warhead’s seeker has been fully demonstrated
in flight tests and is mature. We believe two other technologies, which were
upgraded to create the SM-3 Block 1A, are less mature: the Solid Divert and
Attitude Control System (SDACS) and the Third Stage Rocket Motor. While
some modes of these technologies have been demonstrated in flight tests, the
“pulse mode” of the SDACS, which provides endgame divert for the kinetic
warhead, and the “zero pulse mode” of the Third Stage Rocket Motor, which
increases the missile’s capability against shorter-range threats, have not been
successfully flight-tested. The SDACS operation in pulse mode failed during a
June 2003 flight test. According to program officials, the test failure was a result
of multiple issues with the original design. The program has implemented
changes to address these problems. While recent ground tests have demonstrated
performance of the new configuration, the changes have not yet been flight
tested. A flight test in December 2006 that would have partially demonstrated the
pulse SDACS was not completed because the missile failed to launch. A flight
test that will fully test the new SDACS design is not planned until 2008.
The Third Stage Rocket Motor is capable of three modes of operation, two
of which have been added in Block 2006. While both new modes failed initial
ground testing, one was later successfully flight tested in June 2006 after design
changes. The second, zero pulse mode, has also undergone design changes.
While program officials believe they have a working design and that the missile
can use this mode if needed, it has not yet been flight-tested. The first flight-test
that could demonstrate this capability is not scheduled until fiscal year 2009.
Program officials reported that the design for the SM-3 Block 1A missiles
being produced during Block 2006 is stable with 100 percent of its drawings
released to manufacturing. Although two upgrades to the SM-3 Block 1A missile
have not been fully flight-tested, the program does not anticipate any additional
design changes related to these upgrades.
We did not assess the production maturity of the 22 SM-3 missiles being
procured for Block 2006. Program officials stated that the contractor’s processes
are not yet mature enough to statistically track production processes. The Aegis
BMD program is using other means to assess progress in production and
manufacturing, such as tracking rework hours, cost of defects per unit, and other
defect and test data.
Other Program Issues
The Aegis BMD element builds upon the existing capabilities of
Aegis-equipped Navy cruisers and destroyers. Planned hardware and software
upgrades to these ships will enable them to carry out the ballistic missile defense
mission. In particular, the program is upgrading Aegis destroyers for long-range
surveillance and tracking of intercontinental ballistic missiles. The program plans
to complete the upgrade of 14 destroyers by the end of the Block 2006 period.
In several events, this functionality has been successfully tested, but it has never
been validated in an end-to-end flight test with the GMD system, for which it is
providing long-range surveillance and tracking. Since our last assessment, Aegis
BMD’s planned budget through fiscal year 2009 increased by $362.4 million (4.2
percent), primarily in fiscal years 2008 and 2009. 35
Aegis BMD Program Funding
The Aegis BMD program received $1,122,7 million in FY2007 Missile Defense
Agency (MDA) research and development funds. For FY2008, MDA is requesting
$1,059.1 million in research and development funds for the program. The program
also receives additional Navy funds for efforts such as modifying the SM-2 Block IV
missiles to be used in the near-term (Block 2008) sea-based terminal capability.
Table 3 shows actual or programmed annual funding for the Aegis BMD
program from FY1995 through FY2013.
Government Accountability Office, Defense Acquisitions: Assessments of Selected
Weapon Programs, GAO-07-406SP, March 2007, pp. 27-28.
Table 3. Aegis BMD Program Funding, FY1995-FY2013
(millions of dollars, rounded to the nearest tenth)
Sources: For FY1995 through FY2005: DOD Information Paper provided to CRS by Navy Office
of Legislative Affairs, November 14, 2006. For FY2006-FY2013: FY2008 MDA budget justification
book for Aegis BMD program.
Table 4 shows FY2006-FY2013 MDA funding for the Aegis BMD program by
individual line item.
Table 4. Detailed MDA Aegis BMD Program Funding
(millions of dollars, rounded to nearest tenth)
Aegis Block 2004
Aegis Block 2006
Aegis Block 2008
Aegis Block 2010
Aegis Block 2012
Sea-based terminal Block
Sea-based terminal Block
Amount included in PE
FY06 FY07 FY08 FY09 FY10 FY11 FY12 FY13
254.0 575.6 721.1 592.9 166.1
71.5 162.8 450.6 324.9
26.7 130.3 316.8 412.7 687.8 758.2
893.0 1122.7 1059.1 1129.4 1030.5
987.8 1025.5 1059.3
Source: FY2008 MDA budget justification book for Aegis BMD program.
In addition to the figures shown in the above table, it was reported in February
2007 that MDA planned to seek congressional approval to transfer an additional $20
million in FY2007 funding into the sea-based terminal program from other MDA
accounts. The plan is consistent with congressional report language on the FY2007
The figures in Table 3 and Table 4 do not include Navy funding for modifying
100 SM-2 Block IV missiles for the near-term (Block 2008) sea-based terminal
Potential Allied Programs
Japan. Japan’s interest in BMD, and in cooperating with the United States on
the issue, was heightened in August 1998, when North Korea test-fired a Taepo
Dong-1 ballistic missile that flew over Japan before falling into the Pacific.37 In
addition to cooperating with the United States on development of technologies for
the SM-3 Block II/IIA missile, Japan is modifying four of its Aegis destroyers with
the Aegis BMD 3.6 Block 2004 BMD system between FY2007 and early FY2011,
at a pace of about one ship per year. Under this plan, Japan would have an
opportunity in FY2011 and subsequent years to upgrade the ships’ BMD capability
Chris Johnson, “MDA To Reprogram Funds For Aegis Sea-Based Terminal Missile
Defense,” Inside the Navy, February 26, 2007.
For a discussion, see CRS Report RL31337, Japan-U.S. Cooperation on Ballistic Missile
Defense: Issues and Prospects, by Richard P. Cronin. This archived report was last updated
on March 19, 2002. See also CRS Report RL33436, Japan-U.S. Relations: Issues for
Congress, by Emma Chanlett-Avery, Mark E. Manyin, and William H. Cooper.
to a later Block standard, and to install the Aegis BMD capability on its two
remaining Aegis destroyers. A Japanese Aegis ship participated as a tracking
platform in FTM-10, the June 22, 2006, flight test of the Aegis BMD system. This
was the first time that an allied military unit participated in a U.S. Aegis BMD
intercept test.38 A Japanese ship again tracked a target missile in FTM-11, in
December 2006. Japan is to deploy its first engage-capable Aegis BMD ship in
Other Countries39. Other countries that DOD views as potential naval BMD
operators include South Korea, Australia, the UK, Germany, the Netherlands, Spain,
and Italy. As mentioned earlier, South Korea, Australia, and Spain 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.
The United States has conducted high-level discussions with South Korea about
equipping South Korea’s Aegis destroyers with a BMD capability. South Korea has
expressed interest in a sea-based terminal capability.
The United States signed a memorandum of understanding (MOU) on BMD
with Australia in 2004. The United States and Australia are conducting some
cooperative projects relating to sea-based BMD.
The United States signed an MOU on BMD with the UK in 2003. A U.S.-UK
study on a potential BMD capability for the UK’s planned Type 45 destroyers has
been completed and was scheduled to be briefed in March 2007.
Germany plans to implement a long-range search and track (LRS&T) BMD
capability on some of its ships.
The United States provided pricing data to the Netherlands, and conducted
initial discussions with the Dutch to assess the potential for installing a BMD
capability on certain Dutch ships. The Netherlands is looking at the potential for
integrating the SM-3 missile onto these ships. A Dutch ship participated as a
tracking platform in FTM-11, in December 2006.
Spain might have one of its ships participate as a tracking vessel in FTM-12.
Missile Defense Agency, “Missile Defense Test Results in Successful ‘Hit To Kill’
Intercept,” June 22, 2006 (06-NEWS-0018).
Primary sources for this section: Missile Defense Agency, Frequently Asked Questions,
available online at [http://www.mda.mil/mdalink/html/faq.html]; a briefing on the Aegis
BMD program by Rear Admiral Brad Hicks, Aegis BMD Program Director, to the RUSI 8th
Missile Defense Conference, February 27, 2007.
Sea-Based X-Band Radar (SBX)
General. The Sea-Based X-Band Radar (SBX) is DOD’s other principal seabased BMD element. It is a midcourse fire-control radar designed to support longrange BMD systems. Its principal functions are to detect and establish precise
tracking information on ballistic missiles, discriminate missile warheads from decoys
and debris, provide data for updating ground-based interceptors in flight, and assess
the results of intercept attempts. SBX is intended to support more operationally
realistic testing of the ground-based midcourse system and enhance overall BMD
system operational capability.
SBX is a large, powerful, phased-array radar operating in the X band, a part of
the radio frequency spectrum that is suitable for tracking missile warheads with high
accuracy. The radar is mounted on a modified, self-propelled, semi-submersible oil
platform that can transit at a speed of 8 knots and is designed to be stable in high
winds and rough seas. 40
SBX was completed in 2005 for the Missile Defense Test Bed. The semisubmersible platform was designed by a Norwegian firm and built in Russia. It was
purchased for the SBX program, and modified and integrated with the SBX radar in
Texas. 41 SBX underwent sea trials and high-power radiation testing in the Gulf of
Mexico in 2005. It was then moved by a heavy transport vessel to Hawaii, arriving
there in January 2006. From there, it is to transit to Adak, Alaska, in the Aleutian
Islands, where it is to be homeported and put into operation.
Technical Issues. Technical issues relating to the SBX platform delayed the
SBX’s planned departure for Alaska. A November 2006 press report stated that:
the vessel carrying the radar has sprung leaks and blown out electrical circuits.
Such mundane problems have kept this vital part of the nation’s defense
against missile attacks stuck in the wrong harbor. If all had gone according to
plan, the $950 million radar rig, known as SBX, would be operating now off the
Aleutian Islands in Alaska and ready to defend against threats from North Korea.
Instead, after a three-year odyssey from Norway to Texas and around South
The platform is 238 feet wide and 398 feet long. It measures 282 from its submerged keel
to the top of the radar dome. The SBX has a total displacement of almost 50,000 tons —
about one-half the full load displacement of a Navy aircraft carrier. SBX is operated by a
crew of about 75.
The platform was designed by Moss Maritime, a Norwegian firm, and built for Moss in
2001-2002 by Vyborg shipbuilding, which is located in Vyborg, Russia (a city north of St.
Petersburg, on the Gulf of Finland, that is near the Finnish border). Vyborg Shipbuilding’s
products include semi-submersible oil platforms. Moss sold the platform to Boeing. Boeing
and a subcontractor, Vertex RSI (a part of General Dynamics), modified the platform at the
Keppel AMFELS shipyard in Brownsville, TX. The platform was then moved to Kiewit
Offshore Services of Corpus Christi, TX, where the radar was added by a combined team
of Boeing, Raytheon, Vertex RSI, and Kiewit. (“MDA Completes Integration of X-Band
Radar On Sea-Going Platform,” Defense Daily, April 5, 2005; and “Sea-Based X-band
America, the 28-story-high converted oil platform is in Hawaii, 2,000 miles and
months away from its final destination....
By late 2005, it looked as if SBX might come close to meeting its [end-of2005] target for arriving in Alaska. After trials in the Gulf of Mexico, it was
hauled 15,000 miles around South America — the rig is too big for the Panama
Canal — and it arrived in Hawaii in January of this year . The trip to
Alaska seemed around the corner, but in March, alarms went off in SBX’s engine
room. A leaky valve caused water to flood into SBX’s pontoon. The rig had to
return to Pearl Harbor for repairs to the flaw, which an independent panel later
called a ‘major casualty.’
Then in June , an electrical fault tripped circuit breakers, forcing
SBX back into port for two more weeks of repairs. Such problems are typical
during the initial ‘shakedown’ phase of a new class of ship, says Tom Alexiou,
Boeing’s SBX program manager. Most important, adds Paul Smith, a Boeing
radar manager, there haven’t been major issues in the ‘far more complex’ task
of integrating the radar with other ship systems....
Col. John Fellows, the Pentagon’s manager for SBX, says staying near
Hawaii makes it easier to iron out kinks and join the tests, although officials are
eager for the radar’s permanent deployment. ‘We’re pressured on both sides,’ he
In any case, further issues must be sorted out before the trip to Alaska. The
independent panel hired by the Pentagon concluded in June that while SBX ‘is
an inherently rugged and suitable platform,’ the vessel needs 47 modifications
before it goes into service. Among them: a better plan for operating in harsh
winters and steps to ensure the rig is protected against being rammed by boats.
Senior program officials call the modifications minor and say they have agreed
to almost all of them.
The panel also noted that maintaining morale poses a challenge. SBX’s
crew is composed mostly of defense-industry employees and merchant mariners
hired by Boeing subcontractors. Only a handful of shipmates are servicemen.
Civilian mariners rotate only every 56 days, much longer than work cycles for
comparable oil-industry jobs. Leisure consists of a gym, a basketball hoop on the
deck and movies under the stars, though plasma TVs and more DVDs are on the
Funding for SBX’s mooring in the Aleutians, previously cut in another
headache for project managers, has been restored, but construction won’t be
finished until next August, says Col. Fellows. The latest projection for the trip
to Alaska is sometime next year . 42
The independent assessment referred to in the above-quoted article was
completed in June 2006. The report concluded that SBX:
Jonathan Karp, “A Radar Unit’s Journey Reflects Hopes, Snafus In Missile Defense,”
Wall Street Journal, November 28, 2006: 1. See also Kirsten Scharnberg, “Radar Staying
Longer Than Planned,” Chicago Tribune, September 3, 2006. The article was also
published in the Honolulu Advertiser.
is an inherently rugged and suitable platform for the intended mission[,]
however, the [assessment] panel found that at the current time:
1. Crew Readiness and Materiel Readiness issues indicate that SBX-1
needs additional underway shakedown time and inport time to address crew and
material issues in the Hawaiian area, and
2. Operational Considerations identifies issues for which operational
commanders and developing commands need a full understanding of associated
implications, and which require resolution prior to departure from Hawaii and
operations at the Adak winter MODLOC [modified location] in the Bering Sea. 43
Deployment To Alaska. The SBX reportedly departed Hawaii on January
3, 2007, and arrived in Alaska’s Aleutian Islands on February 7, 2007. The SBX
reportedly withstood winds of 100 miles per hour and 50-foot waves during its transit
to Alaska. 44
March 2007 Tracking Test. MDA announced on March 21, 2007, that on
March 20, the SBX (and also the SPY-1 radars on two Aegis ships) had successfully
tracked a target ballistic missile in a test of radars being incorporated into the overall
U.S. BMD system. 45
Navy To Assume Control. In April 2007, it was reported that the Navy and
MDA had reached a preliminary agreement for the Navy to assume control of the
SBX program. 46
Potential Other Uses. A March 2006 press report states:
Boeing missile defense officials refuse to answer questions about whether
they are developing techniques to produce high-energy weapon effects from the
SBX sea-based radar. However, since large distributed-array devices [like the
SBX] can be focused to deliver large spikes of energy, powerful enough to
disable electronic equipment, the potential is known to exist and is being fielded
on a range of U.S., British and Australian aircraft. 47
SBX-1 Operational Suitability and Viability Assessment, An Independent Assessment.
Arlington (VA), SYColeman, 2006, pp. i-ii. (Final Report, June 2, 2006, Submitted to:
Director, Mission Readiness Task Force, Missile Defense Agency, Submitted by:
Independent Assessment Team, Prepared by: SYColeman, A Wholly Owned Subsidiary of
L-3 Communications). The report is available online at [http://www.pogo.org/m/dp/
“Way Up North,” Defense Daily, February 12, 2007.
Missile Defense Agency News Release, 07-NEWS-0028, 21 March 2007, “Missile
Defense Flight Test Successfully Completed.”
Emelie Rutherford, “Navy To Assume Responsibility For Sea-Based X-Band Radar
Program,” Inside the Navy, April 16, 2007.
“Radar Weapons,” Aerospace Daily & Defense Report, March 20, 2006.
Potential Issues for Congress
Sea-Based Systems in Eventual BMD Architecture
What should be the role of sea-based systems in the eventual national BMD
A key potential issue for Congress concerns the role of sea-based systems in the
eventual U.S. BMD architecture. The eventual architecture is to be defined by U.S.
Strategic Command (USSTRATCOM) — the U.S. military command responsible for
“synchronized DoD effects to combat adversary weapons of mass destruction
worldwide,” including integrated missile defense48 — in consultation with MDA.
Under the evolutionary acquisition approach adopted for the overall U.S. BMD
program, it likely will be a number of years before USSTRATCOM and MDA define
the eventual BMD architecture. 49 Until then, the absence of an objective architecture
might complicate the task of assessing whether the types and numbers of sea-based
BMD systems being acquired are correct. If the role of sea-based systems in the
eventual U.S. BMD architecture turns out to be greater than what DOD has assumed
deciding to equip 18 Aegis ships with BMD capabilities, then additional funding
might be needed to expand the scope of the program to include more than 18 ships.
The issue could also affect the required total number of Navy cruisers and
destroyers. If the role of sea-based systems in the eventual U.S. BMD architecture
turns out to be greater than what the Navy has assumed in calculating its 88-ship
cruiser-destroyer requirement, then the requirement might need to be increased to
something more than 88 ships. Potential oversight questions for Congress include
In the absence of a defined U.S. BMD architecture, what was the
basis for deciding that 18 Aegis ships should be equipped for BMD
operations? What is the likelihood that 18 BMD-equipped Aegis
ships will turn out to be too many or not enough?
What kinds of BMD operations were factored into the Navy
requirement for maintaining a force of at least 88 cruisers and
destroyers? If BMD operations by Navy ships turn out to be more
significant than what the Navy assumed in calculating the 88-ship
figure, will the figure need to be increased, and if so, by how much?
For more on USSTRATCOM, see CRS Report RL33408, Nuclear Command and Control:
Current Programs and Issues, by Robert D. Critchlow. See also USSTRATCOM’s website
at [http://www.stratcom.mil/], from which the quoted passage is taken.
For more on evolutionary acquisition in general, see CRS Report RS21195, Evolutionary
Acquisition and Spiral Development in DOD Programs: Policy Issues for Congress, by
Gary J. Pagliano and Ronald O’Rourke. As ballistic missile threats change over time, it is
possible that the U.S. BMD architecture may never be fully defined.
Replacement for Navy Area Defense (NAD) Program
Has DOD programmed a sufficiently robust sea-based terminal capability to replace
the canceled NAD program?
As discussed in the background section, MDA has programmed a near-term
(Block 2008) and far-term (Block 2014) sea-based terminal capability as the
replacement for the canceled Navy Area Defense (NAD) program. The Block 2014
capability is envisioned as including a new type of missile whose design is not yet
determined. The potential question for Congress is whether DOD’s Block
2008/Block 2014 program is sufficiently robust in terms of the sea-based terminal
capability it will provide, adequate in terms of annual funding levels, and sufficiently
aggressive in terms of the schedule for fielding the planned far-term capability.
Reported options for a new sea-based terminal missile include a system using
a modified version of the Army’s Patriot Advanced Capability-3 (PAC-3) interceptor
or a system using a modified version of the SM-6 Extended Range Active Missile
(SM-6 ERAM) air defense missile being developed by the Navy. 50
In October 2002, it was reported that senior Navy officials
continue to speak of the need for a sea-based terminal BMD capability “sooner
rather than later” and have proposed a path to get there. “The cancellation of the
Navy Area missile defence programme left a huge hole in our developing basket
of missile-defence capabilities,” said Adm. [Michael] Mullen. “Cancelling the
programme didn’t eliminate the warfighting requirement.”
“The nation, not just the navy, needs a sea-based area missile defence
capability, not to protect our ships as much as to protect our forces ashore,
airports and seaports of debarkation” and critical overseas infrastructure
including protection of friends and allies. 51
The above-quoted Admiral Mullen became the Chief of Naval Operations
(CNO) on July 22, 2005.
In July 2004 it was reported that:
The Navy’s senior leadership is rebuilding the case for a sea-based terminal
missile defense requirement that would protect U.S. forces flowing through
foreign ports and Navy ships from short-range missiles, according to Vice Adm.
John Nathman, the Navy’s top requirements advocate.
See, for example, Jason Ma and Christopher J. Castelli, “Adaptation Of PAC-3 For SeaBased Terminal Missile Defense Examined,” Inside the Navy, July 19, 2004; Malina Brown,
“Navy Rebuilding Case For Terminal Missile Defense Requirement,” Inside the Navy, April
Michael Sirak, “Sea-Based Ballistic Missile Defence: The ‘Standard’ Response,” Jane’s
Defence Weekly, October 30, 2002.
The new requirement, Nathman said, would fill the gap left when the
Pentagon terminated the Navy Area missile defense program in December 2001.
... However, he emphasized the Navy is not looking to reinstate the old [NAD]
system. “That’s exactly what we are not talking about,” he said March 24....
The need to bring back a terminal missile defense program was made clear
after reviewing the “analytic case” for the requirement, he said. Though
Nathman could only talk in general terms about the analysis, due to its classified
nature, he said its primary focus was “pacing the threat” issues. Such issues
involve threats that are not a concern today, but could be in the future, he said.
Part of the purpose of the study was to look at the potential time line for those
threats and the regions where they could emerge. 52
Supporters of DOD’s planned program could argue that it replaces enough of
the planned NAD capability, and does so soon enough, to provide Navy ships with
a sufficient degree of terminal defense capability. They could also argue that
attempting to accelerate the Block 2014 effort could increase development risks or
require reducing funding for other BMD programs or other DOD priorities,
increasing operational risks in other areas.
Supporters of programming a more robust sea-based terminal capability could
argue that a full capability for intercepting missiles in the terminal phase could prove
useful, if not critical, for intercepting missiles — such as SRBMs or ballistic missiles
fired along depressed trajectories — that do not fly high enough to exit the
atmosphere and consequently cannot be intercepted by the SM-3. They could also
argue a full NAD replacement program would provide a more robust ability to
counter potential Chinese TBMs equipped with maneuverable reentry vehicles
(MaRVs) capable of hitting moving ships at sea. 53
Aegis Radar Upgrades
Are current plans for upgrading the BMD capabilities of the SPY-1 radars on Navy
Aegis ships appropriate for meeting requirements for sea-based BMD?
As discussed in the background section, current plans for upgrading the radar
capabilities of the Navy’s Aegis cruisers and destroyers include the Aegis BSP,
which forms part of the planned Block 06 version of the Navy’s Aegis BMD
capability. One potential issue for Congress is whether current plans for developing
Malina Brown, “Navy Rebuilding Case For Terminal Missile Defense Requirement,”
Inside the Navy, April 19, 2004.
As discussed in another CRS report, China may now be developing TBMs equipped with
maneuverable reentry vehicles (MaRVs). Observers have expressed strong concern about
this potential development, because such missiles, in combination with a broad-area
maritime surveillance and targeting system, would permit China to attack moving U.S. Navy
ships at sea. The U.S. Navy has not previously faced a threat from highly accurate ballistic
missiles capable of hitting moving ships at sea. Due to their ability to change course,
MaRVs would be more difficult to intercept than non-maneuvering ballistic missile reentry
vehicles. See CRS Report RL33153, China Naval Modernization: Implications for U.S.
Navy Capabilities — Background and Issues for Congress, by Ronald O’Rourke.
and installing the Aegis BSP are adequate and sufficiently funded for meeting
requirements for sea-based BMD. A second potential issue is whether there are other
opportunities for improving the radar capabilities of the Navy’s Aegis cruisers and
destroyers that are not currently being pursued or are funded at limited levels, and if
so, whether funding for these efforts should be increased, so as to better meet
requirements for sea-based BMD.
SM-3 Block II/IIA Missile
If feasible, should the effort to develop the Block II/Block IIA version of the Standard
Missile 3 (SM-3) interceptor missile be accelerated?
Another potential question is whether, if feasible, the effort to develop the Block
II/Block IIA missile should be accelerated, and if so, whether this should be done
even if this requires the United States to assume a greater share of the combined
U.S.-Japan development cost. Views on this issue could be affected by estimates of
when other countries might deploy ballistic missiles of various kinds.
Kinetic Energy Interceptor (KEI)
If the Kinetic Energy Interceptor (KEI) is developed for land-based BMD
operations, should it also be based at sea? If so, what kind of sea-based platform
should be used?
Another potential issue for Congress concerns the Kinetic Energy Interceptor
(KEI) — a new ballistic missile interceptor that, if developed, could be used as a
ground-based interceptor and perhaps subsequently as a sea-based interceptor.
Compared to the SM-3, the KEI would be much larger (perhaps 40 inches in diameter
and 36 feet in length) and would have a much higher burnout velocity. Because of
its much higher burnout velocity, it might be possible to use a KEI based on a
forward-deployed ship to attempt to intercept ballistic missiles during the boost and
early ascent phases of their flights. Development funding for the KEI has been
reduced by Congress in recent budgets, slowing the missile’s development schedule.
DOD, however, plans to increase the budget for KEI significantly over the next
several years. Under current plans, the missile could become available for Navy use
in 2014-2015. 54
The issue is whether the KEI, if developed, should be based at sea, and if so,
what kind of sea-based platform should be used. Basing the KEI on a ship would
require the ship to have missile-launch tubes that are bigger than those currently
installed on Navy cruisers, destroyers, and attack submarines. Potential sea-based
platforms for the KEI include, but are not necessarily limited to, the following:
Government Accountability Office, Defense Acquisitions[:] Assessments of Selected
Major Weapon Programs, GAO-05-301, March 2005, pp. 89-90. See also Thomas Duffy,
“Northrop, MDA Working On KEI Changes Spurred By $800 Million Cut,” Inside Missile
Defense, March 30, 2005: p. 1.
ballistic missile submarines (which have launch tubes large enough
to accommodate the KEI);
surface combatants equipped with newly developed missile-launch
tubes large enough for the KEI; and
a non-combat DOD ship (perhaps based on a commercial hull) or
Supporters of deploying the KEI at sea could argue that it would be more
capable than the SM-3 Block II/IIA for intercepting ICBMs and that it could enable
navy ships to attempt to intercept certain missiles during the boost phase of flight.
Skeptics could argue that in light of other planned BMD capabilities, the need for
basing the KEI at sea is not clear.
Among supporters of basing the KEI at sea, supporters of basing it on ballistic
missile submarines could argue that submarines can operate close to enemy coasts,
in positions suitable for attempting to intercept missiles during their boost phase of
flight, while remaining undetected and less vulnerable to attack than surface
platforms. Skeptics of basing the KEI on ballistic missile submarines could argue
that communication links to submarines are not sufficiently fast to support boostphase intercept operations, and that launching the KEI could give away the
submarine’s location, making it potentially vulnerable to attack.
Supporters of basing the KEI on surface combatants equipped with missilelaunch tubes large enough for the KEI could argue that surface ships have faster
communication links than submarines and more capability to defend themselves than
non-combat ships or floating platforms. Skeptics could argue that surface
combatants might not be able to get close enough to enemy coasts to permit boostphase intercepts, and that the defensive capabilities of a surface combatant are
excessive to what would be needed for a KEI platform operating in the middle of the
ocean, far from potential threats, for the purpose of using the KEI for midcourse
Supporters of a non-combat ship or floating platform could argue that a noncombat ship or floating platform would be suitable for basing the KEI in mid-ocean
locations, far from potential threats, for the purpose of using the KEI for midcourse
intercepts. Skeptics could argue that using such a platform could not be used close
to an enemy coast, for the purpose of attempting a boost-phase intercept, unless it
were protected by other forces.
According to one report, MDA has been studying possibilities for basing the
KEI at sea and was to have selected a preferred sea-based platform in May 2006. 55
Marc Selinger, “MDA To Pick Platform For Sea-Based KEI in May,” Aerospace Daily
& Defense Report, August 19, 2005: 2.
Should procurement of the planned CG(X) cruiser be accelerated?
As a replacement for its 22 Aegis cruisers, the Navy plans to procure 19 new
CG(X) cruisers. The radar capabilities of the CG(X) are to be greater than that of the
Navy’s Aegis ships, and the CG(X) has been justified primarily in connection with
future air defense and BMD operations. Under Navy plans, the first CG(X) is to be
procured in FY2011, and the final ship in FY2023. The Navy had earlier planned to
begin CG(X) procurement in FY2018, but accelerated the planned start of
procurement to FY2011 as part of its FY2006 budget submission. If procured as
planned, the first CG(X) might enter service in 2017, and the final ship might enter
service in 2029. It is possible that limitations on Navy budgets combined with
desires to fund other Navy programs may limit CG(X) procurement to no more than
one ship per year, which would delay the completion of a 19-ship CG(X) program
by several years. 56
If improvements to Aegis radar capabilities are not sufficient to achieve the
desired level of sea-based radar capability for BMD operations, CG(X) radar
capabilities could become important to achieving this desired capability. If so, then
a potential additional issue is whether the planned CG(X) procurement profile would
be sufficient to achieve this desired capability in a timely manner. CG(X) radar
technologies could be introduced into the fleet more quickly by accelerating planned
procurement of CG(X)s or by designing a less expensive ship that preserves CG(X)
radar capabilities while reducing other capabilities less critical to BMD operations,
and then procuring this ship more rapidly than the CG(X) could afford to be
procured. The option of a reduced-cost ship that preserves CG(X) radar capabilities
while reducing other capabilities is discussed in more detail two other CRS reports. 57
Development and Testing of Aegis BMD System
Are there lessons from development and testing of the Aegis BMD system that can
be applied to programs for developing and testing land-based systems?
With eight of ten successful intercepts in eight flight tests, the Aegis BMD
program has achieved a higher rate of successful intercepts than has the ground-based
midcourse system. At least some part of the Aegis BMD program’s higher success
rate may be due to two factors:
The configuration of the Aegis BMD system that has been tested to
date is intended to shoot down shorter-range ballistic missiles. In
general, shorter-range missiles fly at lower speeds than longer-ranged
For more on the CG(X) program, see CRS Report RL32109, Navy DDG-1000 (DD(X))
and CG(X) Ship Acquisition Programs: Oversight Issues and Options for Congress, by
See CRS Report RS22559, Navy CG(X) Cruiser Design Options: Background and
Oversight Issues For Congress, by Ronald O’Rourke; and the “Options For Congress”
section of CRS Report RL32109, op. cit.
missiles, and interceptors intended to shoot down shorter-ranged
ballistic missiles don’t need to be as fast as interceptors intended to
shoot down longer-ranged ballistic missiles. Consequently, the
closing speeds58 involved in intercepts of shorter-ranged ballistic
missiles are generally lower than those for intercepts of longer-ranged
ballistic missiles. Intercepts involving lower closing speeds can be
less difficult to attempt than intercepts involving higher closing
speeds. In BMD tests over more than 20 years, tests of shorter-range
kinetic-energy BMD systems has generally been more successful than
tests of longer-range BMD systems. 59
The Aegis BMD system is being developed as an extension of the
existing Aegis air defense system, and can thus benefit from the
proven radar, software, and interceptor technology of that system,
whereas the ground-based midcourse system is being developed
essentially as a relatively new weapon system.
The potential question is whether these two factors account completely for the
difference in success rates for testing of the Aegis BMD program and the groundbased midcourse program. If they do not, then one potential issue is whether there
is something about the approach adopted for developing and testing the Aegis BMD
capability, compared to that of the ground-based midcourse program that accounts
for part of the difference.
As mentioned earlier, the Aegis BMD program says it has focused since its
inception on the philosophy of “test a little, learn a lot.” It can also be noted that the
Navy has a long history of air-defense missile development programs, and has
established a record of technical discipline, rigorousness, and excellence in areas
such as nuclear propulsion and submarine-launched ballistic missiles. Potential
questions for Congress include the following:
How do the Aegis BMD and ground-based midcourse programs
compare in terms of their approaches for system development and
Are there features of the Aegis BMD program’s approach that, if
applied to the ground-based midcourse program or other U.S. BMD
programs, could improve the development and test efforts for these
Closing speed is the relative speed at which the missile warhead and the interceptor
kinetic kill vehicle approach one another.
For a discussion, see CRS Report RL33240, Kinetic Energy Kill for Ballistic Missile
Defense: A Status Overview, by Steven A. Hildreth.
Potential Allied Programs
Should current efforts to explore the potential for establishing BMD capabilities in
allied navies be reduced, accelerated, or maintained at current levels?
A final potential issue for Congress concerns the potential for establishing BMD
capabilities in allied navies. Should these efforts be reduced, accelerated, or
maintained at current levels? Potential oversight questions for Congress include the
What are the potential military and political advantages and
disadvantages of establishing BMD capabilities in allied navies?
To what degree, if any, would these capabilities be integrated into
the overall U.S. BMD architecture? How, in terms of technology,
command and control, doctrine, and training, would such an
integration be accomplished? If these capabilities are not integrated
into the U.S. architecture, what kind of coordination mechanisms
might be needed to maximize the collective utility of U.S. and allied
sea-based BMD capabilities or to ensure that they do not work at
How might the establishment of BMD capabilities in allied navies
affect U.S. requirements for sea-based BMD systems? To what
degree, if any, could allied BMD ships perform BMD operations
now envisaged for U.S. Aegis ships?
What are the potential implications for regional security of missile
proliferation and proliferation of BMD systems?
Legislative Activity for FY2008
For FY2008, MDA is requesting $1,059.1 million in research and development
funds for the Aegis BMD program.