The Air Force has pulled the plug nearly a year early on Boeing’s [BA] contract to mature technology for the next generation of silo-based, nuclear-tipped intercontinental ballistic missiles, the company said this week.

This is another setback for the incumbent on the current Minuteman III missile fleet, which hoped the remaining year or so of work on its tech-development contract would produce breakthroughs that could persuade the Air Force to unilaterally include Boeing on a team to build the successor to the ICBM, the Ground-Based Strategic Deterrent (GBSD).

“Boeing is disappointed in the Air Force’s decision to not allot additional funding for the GBSD Technology Maturation and Risk Reduction (TMRR) contract,” a Boeing spokesperson wrote Wednesday in an email.”The Boeing team has delivered substantial value under the contract, achieved all contract milestones on time and received strong performance feedback from the Air Force.”

The Washington Post first reported the news Tuesday evening. Boeing is facing stiff, possibly insurmountable, competition from Northrop Grumman [NOC] to build the GBSD.

Boeing has been trying to convince the Air Force to scrap the current competition for the potentially $25 billion GBSD engineering and manufacturing development contract that hit the street over the summer. Boeing quit the race in early July, saying it could not beat Northrop Grumman on price, because its rival owns a solid-fuel rocket motor business: the former Orbital ATK.

Bids for the GBSD engineering and manufacturing development competition are due in December, with an award in 2020. Boeing declined to say Wednesday if it would protest. Frank McCall, a Boeing GBSD executive, did not rule out that option in a September media gaggle.

Boeing and Northrop Grumman were each awarded three-year development contracts in 2017 to develop GBSD prototypes, and both had been expected to compete to produce the ICBM. Boeing’s technology maturation and risk reduction contract was worth $349.2 million: good for an average annual value of just over $115 million.

The GBSD will carry W87-1-style warheads provided by the Department of Energy’s National Nuclear Security Administration. The warheads will fly in Mk-21 re-entry vehicles. Lockheed Martin is developing the technology to fit the Mk-21 re-entry vehicles aboard GBSD missiles, under an Air Force contract worth up to $138 million over four years. That includes about $100 million in firm funding over a three-year base.