The next-generation, nuclear-armed, intercontinental ballistic missile that Boeing [BA] has vowed not to prime would get $65 million more than the White House requested for 2020, if a bill advanced Tuesday by a Senate Appropriations panel became law.

The Ground Based Strategic Deterrent (GBSD) program would receive $635 million for the fiscal year that begins Oct. 1, under the 2020 Defense Appropriations Act that the Senate Appropriations defense subcommittee on Tuesday sent on to the full Committee for a more extensive markup on Thursday.

As foreshadowed by the legislative debates of the summer, Tuesday’s markup sets the Republican-controlled Senate up for a showdown with the House, where majority Democrats have approved $462 million for GBSD in a bid to slow development of the launchers slated to replace some 400 1970s-vintage Minuteman III missiles starting in 2030.

The proposed House GBSD budget for 2020 is more than 11% above the 2019 budget, but about 20 percent below what the administration requested for the final year of a three-year GBSD technology development competition between Minuteman III maker Boeing and Northrop Grumman [NOC] — the latter of which is now the only company publicly interested in building and deploying the next generation missile.

In July, Leanne Caret, chief executive officer of Boeing Defense, Space & Security, wrote to the Pentagon in a letter leaked to the press that Boeing would not bid on a potentially $25 billion Air Force contract to build and deploy GBSD. 

The Air Force planned to award the GBSD manufacturing contract by September 2020. The service has said it will acquire more than 600 missiles and deploy about 400, beginning around 2030.

Whether GBSD deployment begins — and ends — on time depends on more than the Air Force’s procurement strategy. 

The Department of Energy’s semiautonomous National Nuclear Security Administration (NNSA), still has to start up production of GBSD’s W87-1 warhead, beginning with the fissile plutonium cores, or pits, of the weapons. The NNSA plans to support GBSD by cranking out 80 pits annually at upgraded manufacturing facilities Los Alamos National Laboratory in New Mexico and a planned new pit plant at the Savannah River Site in Aiken, S.C. 

As with GBSD itself, House appropriators moved to throttle back pit funding in 2020, recommending about $470 million for the NNSA Plutonium Sustainment account that funds both Los Alamos and Savannah River pit infrastructure. That is about $240 million less than requested. House appropriators are skeptical that the NNSA needs as much money as the agency requested for the planned Savannah River plant.

Senate appropriators will not reveal their preferred funding for the NNSA pit account until Thursday, when the full Appropriations Committee is scheduled to mark up both its 2020 Defense and Energy and Water appropriations bills.