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May 10, 2021
Navy Next-Generation Attack Submarine (SSN[X]) Program:
Background and Issues for Congress
Introduction and Issue for Congress
VA. These are the only two shipyards in the country
The Navy wants to begin procuring a new class of nuclear-
capable of building nuclear-powered ships. GD/EB builds
powered attack submarine (SSN), called the Next-
submarines only, while HII/NNS also builds nuclear-
Generation Attack Submarine or SSN(X), in FY2031. The
powered aircraft carriers and is capable of building other
SSN(X) would be the successor to the Virginia-class SSN
types of surface ships.
design, which the Navy has been procuring since FY1998.
Congress approved $1 million in initial research and
Figure 1. Virginia-Class Attack Submarine (SSN)
development funding for the SSN(X) program in FY2021.
An issue for Congress for FY2022 and subsequent years is
whether to approve, reject, or modify the Navy’s funding
requests and acquisition strategy for the SSN(X) program.
Congress’s decisions on this issue could affect Navy
capabilities and funding requirements and the U.S.
shipbuilding industrial base.
Submarines in the U.S. Navy
The U.S. Navy operates three types of submarines—
nuclear-powered ballistic missile submarines (SSBNs),
nuclear-powered cruise missile and special operations
Source: Cropped version of photograph accompanying Dan Ward,
forces (SOF) submarines (SSGNs), and nuclear-powered
attack submarines (SSNs). The SSNs are general-purpose
“Opinion: How Budget Pressure Prompted the Success of Virginia-
submarines that can perform a variety of peacetime and
Class Submarine Program,” USNI News, November 3, 2014. The
caption states that it shows USS Minnesota (SSN-783) under
wartime missions.
construction in 2012, and credits the photograph to the U.S. Navy.
Virginia-Class Program
Since FY2011, Virginia-class SSNs (Figure 1) have been
procured at a rate of two boats per year, and a total of 34
In addition to GD/EB and HII/NNS, the submarine
have been procured through FY2021. Most Virginia-class
construction industrial base includes hundreds of supplier
boats procured in FY2019 and subsequent years are to be
firms, as well as laboratories and research facilities, in
built with the Virginia Payload Module (VPM), an
numerous states. Much of the material procured from
additional, 84-foot-long, mid-body section equipped with
supplier firms for the construction of submarines comes
four large-diameter, vertical launch tubes for storing and
from sole-source suppliers. For nuclear-propulsion
launching Tomahawk cruise missiles or other payloads.
component suppliers, an additional source of work is the
When procured at a rate of two boats per year, VPM-
Navy’s nuclear-powered aircraft carrier construction
equipped Virginia-class SSNs have an estimated
program.
procurement cost of about $3.4 billion per boat.
SSN(X) Program
For additional background information on submarines in
the U.S. Navy, the Virginia-class SSN program, and the
Program Designation
In the designation SSN(X), the “X” means that the exact
Columbia-class SSBN program, see CRS Report RL32418,
Navy Virginia (SSN-774) Class Attack Submarine
design of the boat has not yet been determined.
Procurement: Background and Issues for Congress, by
Ronald O'Rourke, and CRS Report R41129, Navy
Procurement Schedule
Under the Navy’s FY2020 30
Columbia (SSBN-826) Class Ballistic Missile Submarine
-year (FY2020-FY2049)
Program: Background and Issues for Congress, by Ronald
shipbuilding plan, the first SSN(X) would be procured in
O'Rourke.
FY2031, along with a single Virginia-class boat. In FY2032
and FY2033, the final four Virginia-class boats would be
Submarine Construction Industrial Base
procured, at a rate of two per year. Procurement of follow-
U.S. Navy submarines are built by General Dynamics’
on SSN(X)s, at a rate of two per year, would then begin in
Electric Boat Division (GD/EB) of Groton, CT, and
FY2034. The 30-year plan’s sustained procurement rate of
Quonset Point, RI, and Huntington Ingalls Industries’
two SSNs per year would achieve a force of 66 SSNs —the
Newport News Shipbuilding (HII/NNS), of Newport News,
Navy’s current SSN force-level goal—in FY2048.
https://crsreports.congress.gov
Navy Next-Generation Attack Submarine (SSN[X]) Program: Background and Issues for Congress
A subsequent 30-year Navy shipbuilding document that the
budget, PE 0604850N was line 150 in the Navy’s research
Trump Administration released on December 9, 2020—a
and development account. For FY2021, the Navy requested
document that can be viewed as the Trump
$1 million for PE 0604850N. Congress, as part of its action
Administration’s final published vision for future Navy
on the Navy’s proposed FY2021 budget, approved this
force structure and/or a draft version of the FY2022 30-year
request.
shipbuilding plan—proposed a new SSN force-level goal of
72 to 78 boats. To meet this goal by the latter 2040s, it
Navy research and development funding in FY2020 and
projected an SSN procurement rate of three boats per year
prior years has supported studies and technology
during the period FY2035-FY2041, and two and two-thirds
development efforts that can be applied to future
boats per year (in annual quantities of 2-3-3) during the
submarines, including the SSN(X). If the SSN(X) program
period FY2042-FY2050.
follows the pattern of previous Navy submarine acquisition
programs, the SSN(X) program’s annual research and
Design of the SSN(X)
development funding requests in coming years would
The Navy states that the SSN(X)
increase to tens of millions of dollars per year, and
eventually to hundreds of millions of dollars per year. In
will be designed to counter the emerging threat
addition to funding in PE 0604850N, funding for
posed by near peer adversary competition for
developing the SSN(X)’s reactor plant might be provided
undersea supremacy. Unlike the VIRGINIA Class
through PE 0603570N (Advanced Nuclear Power Systems),
Submarine, which was designed for multi-mission
the PE that has been used in the past for funding the
dominance in the littoral, SSN(X) will be designed
development of reactor plants for other Navy nuclear-
for greater transit speed under increased stealth
powered ships.
conditions in all ocean environments, and carry a
Issues for Congress
larger inventory of weapons and diverse payloads.
While SSN(X) will be designed to retain multi-
Issues for Congress include the following:
mission capability and sustained combat presence
whether the Navy has accurately identified the
in denied waters, renewed priority of the anti-
SSN(X)’s required capabilities and accurately analyzed
submarine warfare (ASW) mission against
and incorporated the impact that various required
sophisticated threats in greater numbers will
capabilities can have on the SSN(X)’s procurement cost
influence the design trade space. SSN(X) will be
and life-cycle operation and support (O&S) cost;
required to defend against threat UUVs [unmanned
underwater vehicles], and coordinate with a larger
the potential impact of the SSN(X) program—given the
contingent of off-hull vehicles, sensors, and
design’s currently estimated unit procurement cost and
friendly forces.
potential future Navy funding levels—on funding that
(Budget-justification book for FY2021 Research,
will be available for other Navy program priorities; and
Development, Test, and Evaluation, Navy account,
Vol. 3 [Budget Activity 5], p. 1365.)
whether each SSN(X) should be built jointly by GD/EB
and HII/NNS (the approach that has been used for
The Navy is examining three broad design options for the
building Virginia-class SSNs and, in modified form, is
SSN(X)—a design based on the Virginia-class SSN design,
to be used for building Columbia-class SSBNs), or
a design based on the Columbia-class SSBN design, and a
whether individual SSN(X)s should instead be
brand new design. An industry official stated that the
completely built within a given shipyard (the separate-
SSN(X) might have a beam (i.e., hull diameter) greater than
yard approach used for building earlier Navy SSNs and
that of the Virginia-class design (34 feet), and closer to that
SSBNs).
of the Navy’s Seawolf-class SSN design and Columbia-
class SSBN design (40 and 43 feet, respectively).
Regarding the final issue above, the Navy and Congress
chose the joint-production strategy for the Virginia-class
Potential Procurement Cost
program as a means of preserving two U.S. submarine
Based on the Navy’s desired capabilities for the SSN(X),
construction shipyards during an expected period of
the Navy and the Congressional Budget Office (CBO)
relatively low annual submarine procurement rates. For the
expect the SSN(X) to be substantially more expensive to
SSN(X) program, factors to consider include the expected
procure than the Virginia-class design. An April 2021 CBO
future submarine procurement rate; the impact that shifting
report on the December 9, 2020, 30-year Navy shipbuilding
back to separate-yard production might have on the Navy’s
document states that in constant FY2021 dollars, the
ability to use competition in awarding SSN(X) construction
SSN(X)’s average unit procurement cost is estimated at
contracts; and the feasibility and cost of shifting back to
$5.8 billion by the Navy and $6.2 billion by CBO.
separate-yard production after more than 20 years of joint
production.
Funding
Funding for the SSN(X) program is currently provided in
Ronald O'Rourke, Specialist in Naval Affairs
the Navy’s research and development account, and
specifically in Project 2368 (SSN[X] Class Submarine
IF11826
Development), which is the only project within Program
Element (PE) 0604850N (SSN[X]). In the Navy’s FY2021
https://crsreports.congress.gov
Navy Next-Generation Attack Submarine (SSN[X]) Program: Background and Issues for Congress
Disclaimer
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https://crsreports.congress.gov | IF11826 · VERSION 1 · NEW