U.S. Air Force Tests Mk21A Reentry Vehicle for Sentinel's Nuclear Warhead

The U.S. Air Force conducted an unarmed flight test of Lockheed Martin's Mk21A reentry vehicle, a component being developed to carry the W87-1 nuclear warhead on the future LGM-35A Sentinel intercontinental ballistic missile. The test used a Northrop Grumman Minotaur I launch vehicle from Vandenberg Space Force Base to collect information about flight performance and environmental conditions without carrying a nuclear payload. Mk21A development remains separate from both Sentinel missile fielding and warhead production, which are still subject to program schedules. The service has not released detailed test performance results or announced an operational deployment date.