NNSA completes requirements review of GBSD's W87-1 warhead

The National Nuclear Security Administration has finished a requirements review of the W87-1 warhead that will eventually be deployed with the new Ground Based Strategic Deterrent's intercontinental ballistic missiles.

The program conducted the review with its military customer, the Air Force, between September 2020 and March 2021, an NNSA spokeswoman told Inside Defense in an email Wednesday. It’s a key milestone as the W87-1 effort nears the end of the “feasibility study and design options” phase and shifts into the “design definition and cost study” phase later this fiscal year.

As that transition nears, NNSA’s cost evaluation and program evaluation office has begun conducting an independent review of the W87-1’s price tag, which is slated to be completed in June, the agency’s spokeswoman said.

NNSA estimated in December 2018 the new warhead would cost between $8.6 billion and $14.8 billion, according to a Government Accountability Office audit released in September.

The Office of the Secretary of Defense, meanwhile, recently estimated GBSD will cost $264 billion over its 50-year life cycle.

The W87-1 will replace the W78 warheads that are currently deployed with the military’s Minuteman III ICBM system. Along with the new GBSD missiles, Mk21A reentry vehicle and arming and fuzing assembly that the Air Force is currently developing, the W87-1 will modernize the land-based leg of the nuclear triad.

The Pentagon plans to begin fielding GBSD missiles in 2029 with legacy W78 warheads. The new W87-1 program, meanwhile, is on track for its first production unit milestone in 2030.