Supply Chain Disruption, Design Delays, Cost Overruns Cloud US ‘Nuclear Triad’ Upgrades: Pentagon Officials

President Joe Biden’s $863 billion Fiscal Year 2024 [FY24] defense budget request includes $23.8 billion for the United States Department of Energy [DOE] to produce nuclear weapons and manage the nation’s strategic stockpile and $37.7 billion for the Pentagon to operate its “nuclear enterprise.”

That “nuclear enterprise” is America’s land-air-sea “triad” strategic force posture—intercontinental ballistic missiles [ICBMs], strategic bombers, and “boomer” submarines armed with submarine-launched ballistic missile [SLBMs].

All three “triad” legs are being upgraded in a “once-in-a-generation modernization” with the Sentinel ICBM replacing the Minute Man III, the December 2022 introduction of the B-21 strategic bomber, and a 12-ship fleet of new Columbia-class SLBM “boomers” to succeed the Navy’s 14-ship Ohio-Class sub force by 2030.

It all looks good on paper, but supply chain issues, design delays, and cost overruns are disrupting transitions to the new platforms as the United States and its allies face increasing nuclear threats from Vladimir Putin’s Russia, the Peoples’ Republic of China [PRC], North Korea, and, potentially, soon Iran, with mounting fears of proliferation to non-nation entities fostering a wildcard of uncertainty.

During a March 28 hearing before the House Armed Services Committee’s Strategic Forces Subcommittee, three assistant secretaries of defense and Air Force and Navy strategic force commanders raised alarm about delays that could require the triad to rely on extending the operational lifespans of obsolete weapon systems with limited stockpiles from now-defunct supply lines.

“Supply chains responsible for legacy system parts are closing, and require innovation to fill those gaps,” Air Force Global Strike Command Commander Gen. Thomas Bussiere said in his testimony, noting those transitional “gaps” mean the United States “must maintain our legacy weapon systems at full operational capability until the future force is ready to take on the operational requirement.”

“Replacement programs are ongoing, but there is little or no margin between the end of [the] useful life of existing programs and the fielding of their replacements,” Assistant Secretary of Defense for Nuclear, Chemical, and Biological Defense Programs Deborah Rosenblum testified. 

New Ballistic Missile: The Sentinel

The Biden administration’s FY24 budget request includes $4.3 billion for the Sentinel ICBM to replace the Minuteman III missiles, which are “aging out and have been life-extended multiple times since its initial deployment in 1970—well past its original 10-year design life,” Assistant Secretary of Defense for Space Policy Dr. John Plumb testified.

About 400 of the 50-year-old ICMBs are stationed in silos on 20th Air Force installations across North Dakota, Wyoming, Montana, Nebraska, and Colorado. The Sentinels, currently in the “engineering and development phase,” are scheduled to be deployed from 2029 through 2036 and be operational through 2075.

There’s some concern the new system may not be operational until the early 2030s.

“The program is executing an aggressive schedule, and the Air Force is actively working to mitigate risks in delivering this capability to meet [the nation’s strategic] requirements,” Rosenblum said.

The missile system, which will carry a new W87-1 warhead, features “increased capability, enhanced security, improved reliability, and lower lifecycle sustainment costs compared to the Minute Man III,” Plumb said.

“This will ensure Sentinel has the adaptability and flexibility to address a changing threat environment, [and] contribute to the credibility of the overall nuclear triad” through the 2070s.

Bussiere praised the “ingenuity” of Air Force missileers in maintaining ICBMs older than some of their fathers.

“We continue to provide critical sustainment programs to maintain our MMIII’s lethality through the end of life, and our forces remain ready to transition to on-time fielding of Sentinel, our new ground-based strategic deterrent,” he said.

The 50-year-old Minute Man ICBM is housed in silos that are decades older, he said.

More than “150 ICBM launch vehicles and operational ground equipment components require risk mitigation to remain operationally viable until their end-of-life,” Bussiere said.

“The missile wings have logged over 2.4 million maintenance hours over the last five years, which is a 30 percent increase over the previous five years.”

Nevertheless, he said, 20th Air Force bases carry a maintenance backlog of 21,000 work orders “and models predict a 25-percent increase” in maintenance demands in the coming years.

New Bomber: B-21 Raider

The Pentagon’s budget request includes $5.3 billion for the new B-21 Raider bomber and $978.2 million for a new ‘Long-Range Standoff’ [LRSO] cruise missile, equipped with a W80-4 warhead, and modernization upgrades to the B-52 bomber.

“The B-21 will be a key component of the United States’ conventional and nuclear-capable deep-strike capabilities, providing a visible and flexible deterrent capability that can also penetrate and survive highly contested threat environments around the world,” Plumb said, noting only $2.3 billion of the $5.3 billion is for the B-21, “allowing the program to transition to low-rate initial production.”

The LRSO will replace a cruise missile in use since 1982 and is “necessary to maintain the viability of the B-52 fleet,” he said, adding they will also be fitted on B-21s.

“These investments in the modernization of dual-capable F-35 aircraft and B61 gravity bombs are critical to ensuring that the United States can contribute to the security of its NATO allies with modernized nuclear deterrent capabilities,” Plumb said.

Rosenblum said the B-21 will replace the B-2 and B-1 bombers. The B-1 is for conventional use only. The B-21 will also have the conventional capacity in addition to its strategic mission, she said.

The B-21, built by Northrop Grumman, is expected to make its first flight in 2023 and enter service by 2027. Each one is projected to cost nearly $700 million. The Air Force states it will order at least 100 in the coming years.

Bussiere said the B-21 Raider “will offer … unparalleled capabilities, but until it is mission capable, we must be postured to deter and, if necessary, fight with our current force of B-1, B-2, and B-52 bomber aircraft” with the B-52 continuing to be “the workhorse” of the Air Force’s long-range strike bomber fleet for at least the next decade.

The B-52 faces “sustainment challenges. Parts obsolescence increases aircraft downtime and leads to higher cannibalization rates of parts from other aircraft,” he said.

“This means to meet mission requirements, aircrews are flying less training sorties. A lack of training sorties leads to a lack of current aircrew to fly mission lines and an inability to absorb the number of crews required.”

New Boomer: Columbia Class

The FY24 budget request includes $6.2 billion for a second Columbia-class nuclear-powered ballistic missile submarine [SSBN], which will replace the current fleet of Ohio-class SSBNs “as the most survivable leg of the nuclear triad,” Plumb said.

The first of the new “boomer” submarines—USS District of Columbia—began construction in October 2020 and is scheduled to enter service in 2031, the first of 12 Columbia Class submarines that will replace the fleet of 14 Ohio Class SSBNs.

Beginning in 2027, the Navy hopes to order a new $6.2 billion Columbia a year until the 12-ship fleet is filled out. The 560-foot missile boats have 16 tubes and will be manned by a 155-member crew.

Plumb called the Columbia Class submarines the DOD’s “top acquisition priority,” saying the “boomers” will “ensure the effectiveness and availability of the sea leg of the triad through the 2080s.”

The budget request also includes $456.6 million for Trident II SLBM “life extension” to make them viable through the 2080s.

“We need to fully fund the Columbia Class SSBN program to deliver a minimum of 12 boats on time, as the Ohio Class SSBNs begin to retire,” Rosenbaum said.

“We also need to continue to prioritize near-term investments in the submarine industrial base.”