The prime contractor for the Ground Based Strategic Deterrence wrapped up a key review for the program and set a cost and schedule baseline for the Air Force’s next-generation, nuclear-tipped intercontinental ballistic missile.

Northrop Grumman [NOC], which holds a $13 billion Air Force engineering and manufacturing development contract to build the first tranche of Ground Based Strategic Deterrent (GBSD) missiles, announced the milestone in an April 7 press release

. The company did not share the details of the GBSD baseline and a spokesperson did not immediately respond to a request for that information.

The Air Force plans to replace its 400 deployed Minuteman III, silo-based, intercontinental missiles with GBSD missiles and order another 259 missiles for spares and testing. Acquisition costs will be at least $95 billion, while total life cycle costs could reach $264 billion, according to government estimates. The Air Force wants GBSD to achieve its initial operational capacity by 2029.

GBSD initially will use W87-0 warheads provided by the Department of Energy’s National Nuclear Security Administration (NNSA). The 87-0 will be a Minuteman III warhead adapted for use on GBSD. Flight certification for the GBSD variant could start in the next several years, the Air Force has said. Later GBSD missiles will use W87-1 warheads, essentially freshly built copies of W87-0, but with brand new plutonium pits and modern components.

Some members of the House Democratic caucus have shown an appetite to either cancel or delay GBSD. Disarmament-advocating non-government groups have pushed a GBSD delay, with a concurrent Minuteman III force reductions and life-extensions, as a means of protecting other Pentagon programs from budget cuts in the short term.

Last week, an official with the NNSA’s Lawrence Livermore National Laboratory in California told an audience of Washington insiders and nuclear-policy watchers that GBSD has broad, but not deep, support in Congress, and that the program could be bartered during deal-cutting during President Joe Biden administration’s first federal budget cycle. Livermore designed the W87.