Sentinel program

The Sentinel program, formerly the Ground Based Strategic Deterrent or GBSD, is the United States Air Force effort to replace the roughly fifty-year-old Minuteman III intercontinental ballistic missile, the land-based leg of the nuclear triad. The Air Force Nuclear Weapons Center selected Northrop Grumman on 8 September 2020 for a 13.3 billion dollar engineering and manufacturing development contract expected to span about 8.5 years. The plan covers a new missile, a modernized weapon system command and control network and the restoration of launch facilities and control centers across several states, with earlier requests calling for about 400 missiles carrying the existing Mk12A and Mk21 reentry vehicles. GlobalSecurity.org reports an initial operational capability target of 2029 and full operational capability in 2036, so the system is still in development and has not been fielded.