https://crsreports.congress.gov
Updated July 23, 2024
Navy Next-Generation Attack Submarine (SSN[X]) Program:
Background and Issues for Congress
Introduction
The Navy has been procuring Virginia-class nuclear
powered attack submarines (SSNs) since FY1998. The
Navy’s envisaged successor to the Virginia-class design is
the Next-Generation Attack Submarine, or SSN(X). The
Navy’s FY2024 budget submission envisaged procuring the
first SSN(X) in FY2035. The Navy’s FY2025 budget
submission defers the envisaged procurement of the first
SSN(X) from FY2035 to FY2040 due, the Navy states, to
limitations on the Navy’s total budget.
Submarines in the U.S. Navy
The U.S. Navy operates nuclear-powered ballistic missile
submarines (SSBNs), nuclear-powered cruise missile and
special operations forces (SOF) submarines (SSGNs), and
nuclear-powered attack submarines (SSNs). The SSNs are
general-purpose submarines that can perform a variety of
peacetime and wartime missions.
Virginia-Class Program
When procured at a rate of two boats per year, Virginia-
class SSNs (Figure 1) equipped with the Virginia Payload
Module (VPM) have a current estimated procurement cost
of more than $4.5 billion per boat. For additional
information on Navy submarine programs, see CRS Report
RL32418, Navy Virginia-Class Submarine Program and
AUKUS Submarine (Pillar 1) Project: Background and
Issues for Congress, by Ronald O'Rourke, and CRS Report
R41129, Navy Columbia (SSBN-826) Class Ballistic
Missile Submarine Program: Background and Issues for
Congress, by Ronald O'Rourke.
Figure 1. Virginia-Class Attack Submarine (SSN)
Source: Cropped version of photograph accompanying Dan Ward,
“Opinion: How Budget Pressure Prompted the Success of Virginia-
Class Submarine Program,” USNI News, November 3, 2014. The
caption states that it shows USS Minnesota (SSN-783) under
construction in 2012 and credits the photograph to the U.S. Navy.
Submarine Construction Industrial Base
U.S. Navy submarines are built by General Dynamics’
Electric Boat Division (GD/EB) of Groton, CT, and
Quonset Point, RI, and Huntington Ingalls Industries’
Newport News Shipbuilding (HII/NNS), of Newport News,
VA. These are the only two shipyards in the country
capable of building nuclear-powered ships. GD/EB builds
submarines only, while HII/NNS also builds nuclear-
powered aircraft carriers. The submarine construction
industrial base also includes hundreds of supplier firms, as
well as laboratories and research facilities, in numerous
states. Much of the material procured from supplier firms
for building submarines comes from sole-source suppliers.
SSN(X) Program
Program Designation
In the designation SSN(X), the “X” means that the exact
design of the boat has not yet been determined.
Procurement Schedule
The Navy’s FY2024 budget submission envisaged
procuring the first SSN(X) in FY2035. The Navy’s FY2025
budget submission defers the envisaged procurement of the
first SSN(X) from FY2035 to FY2040. The Navy’s FY2025
30-year (FY2035-FY2054) shipbuilding plan states: “The
delay of SSN(X) construction start from the mid-2030s to
the early 2040s presents a significant challenge to the
submarine design industrial base associated with the
extended gap between the Columbia class and SSN(X)
design programs, which the Navy will manage.”
Design of the SSN(X)
The Navy states that the SSN(X) “will be designed to
counter the growing threat posed by near peer adversary
competition for undersea supremacy. It will provide greater
speed, increased horizontal [i.e., torpedo-room] payload
capacity, improved acoustic superiority and non-acoustic
signatures, and higher operational availability. SSN(X) will
conduct full spectrum undersea warfare and be able to
coordinate with a larger contingent of off-hull vehicles,
sensors, and friendly forces.” (Budget-justification book for
FY2025 Research, Development, Test, and Evaluation,
Navy account, Vol. 3 [Budget Activity 5], p. 1299.)
Navy officials have stated that the Navy wants the SSN(X)
to incorporate the speed and payload of the Navy’s fast and
heavily armed Seawolf (SSN-21) class SSN design, the
acoustic quietness and sensors of the Virginia-class design,
and the operational availability and service life of the
Columbia-class design. These requirements will likely
result in an SSN(X) design that is larger than the original
Virginia-class design, which has a submerged displacement
of about 7,800 tons, and possibly larger than the original
