"The @usairforce Nuclear Weapons Center & @northropgrumman conducted a static fire test earlier this month of the LGM-35A Sentinel #ICBM, set to replace the Minuteman III as the land based and most responsive leg of the US Nuclear Triad," Air Force Global Strike Command said via Twitter.
The LGM-35 Sentinel is a future US land-based intercontinental ballistic missile system, which is currently in the early stages of development. The Minuteman III program started at the height of the Cold War and this weapon has been in service since the 1970s.