Sentinel ICBM Exceeds Projected Cost by 37 Percent

March 2024
By Libby Flatoff

The U.S. Air Force notified Congress on Jan. 18 that the new Sentinel intercontinental ballistic missile (ICBM) would cost 37 percent more than expected and take about two years longer than planned to build and deploy.

The cost per unit for the Sentinel system originally was projected to be $118 million and now is estimated at $162 million, putting the projected total program cost at roughly $120 billion over the next decade, up from an estimated baseline of $96 billion, the Air Force told Defense News.

The expected delay of the system’s initial operating capability likely will result in greater sustainment costs to keep the existing fleet of Minuteman III ICBMs operational.

The projected overrun would put the new missile system in “critical” breach of the Nunn-McCurdy Act, a law designed to prevent major cost overruns for weapons systems, a chronic problem plaguing the Pentagon.

There are two levels of breaches under the act. A program is in significant breach when the program unit cost increases by 15 percent of the current baseline or 30 percent over the original cost estimate. A critical breach occurs when the cost increases by 25 percent of the current baseline or 50 percent of the original estimate.

In 2020, Northrop Grumman was awarded a sole-source $13.3 billion contract for engineering and manufacturing Sentinel missiles to replace the current arsenal of 400 deployed Minuteman III ICBMs.

The Sentinel development program calls for acquiring 659 missiles, updating 450 launch silos, and modernizing more than 600 facilities to “like new conditions,” according to Air Force Global Strike Command. (See ACT, May 2023.)

In 2020 the Pentagon estimated that the total cost of the next-generation Sentinel program, including decades of operations and support, could be as high as $264 billion. (See ACT, March 2021.) Taking the new cost increases into account, the total cost of the program over its planned 50-year life cycle could be as high as $300 billion, plus another $15 billion for the production of the new W87-1 warhead for the missiles.

Under the act, the Defense Department is required to report to Congress whenever a major defense acquisition program exceeds certain cost thresholds. The notification must include an explanation of the cost increase, changes in the projected cost, changes in performance or schedule, action taken or proposed to control cost growth, and prior cost estimating information.

In addition, the department must submit a new selected acquisition report containing the new status of the total program cost, schedule, performance, cost per unit, and cost breach information. The report on the Sentinel program is due to be submitted within 45 days after President Joe Biden submits his budget to Congress, now set for March 9.

With a critical breach, the Office of the Secretary of Defense is required to conduct a root-cause analysis to determine what factors caused the cost increase.

Under the act, if the program is to continue, the defense secretary must certify no later than 60 days after the new selected acquisition report that the program is essential to national security, the new cost estimates are reasonable, the program is a higher priority than those whose funding will be cut to cover the cost increase, and a new management structure is in place to control additional cost growth. If the certification and requirements are met, the program will be allowed to continue.

At the Air Force Association forum on Feb. 11, Air Force Secretary Frank Kendall said that “nothing is off the table right now.… [W]e’re going to take a look at the totality of the [defense] budget” when addressing how to cover the additional $35 billion needed for the Sentinel program.

Rep. John Garamendi (D-Calif.), a member of the House Armed Services Committee and co-chair of the bicameral Nuclear Weapons and Arms Control Working Group, argued in a statement Jan. 18 that the overrun is “proof that we must look closely at our nation’s nuclear policies…[and] address our security needs without compromising fiscal responsibility.”

Some experts, such as Gabe Murphy, a national security policy analyst with Taxpayers for Common Sense, say that the United States should get rid of ICBMs entirely. “Whatever strategic value nuclear ICBMs may have held in the past, in our current security environment, they serve as little more than a bottomless pit…[into] which the Pentagon throws taxpayers’ hard-earned money,” Murphy wrote in an Feb. 11 essay for Stars and Stripes.

In 2016, former Defense Secretary William Perry wrote in The New York Times “that the United States can safely phase out” its land-based ICBM force. He argued that although the ICBM force is too costly and dangerous, submarine and bomber forces are highly accurate and thus are “sufficient to deter our enemies and will be for the foreseeable future.”

Despite the cost increases, congressional backers of the Sentinel program say it should go full-speed ahead. “Sentinel is absolutely necessary for the future of our nuclear deterrent. I’m committed to conducting vigorous oversight of the program and ensuring the Air Force follows through on making the necessary changes to address the cost overruns while continuing to advance the program,” House Armed Services Committee Chairman Mike Rogers (R-Ala.) said in a Jan. 19 press statement.

Others urged support for Sentinel whatever the cost. “Despite these challenges, abandoning or downsizing Sentinel isn’t an option. Our nation’s safety and prosperity depend on an updated and fully operational nuclear deterrent,” argued Sens. Roger Wicker (R-Miss.) and Deb Fischer (R-Neb.), the ranking members of the Senate Armed Services Committee and its strategic forces subcommittee, respectively, on Jan. 19 in The Wall Street Journal.