The Mark 21 nuclear bomb was a United States thermonuclear gravity bomb first produced in 1955. It was based on the TX 21 "Shrimp" prototype that had been detonated during the Castle Bravo test in March 1954.

2023年10月31日 · WASHINGTON — Lockheed Martin has been awarded nearly $1 billion to develop a new reentry vehicle for the LGM-35A Sentinel intercontinental ballistic missile (ICBM), the Pentagon announced Monday...

The W87 is an American thermonuclear missile warhead formerly deployed on the LGM-118A Peacekeeper ("MX") ICBM. 50 MX missiles were built, each carrying up to 10 W87 warheads in multiple independently targetable reentry vehicles (MIRV), and were deployed from 1986 to 2005.

The Mark 21 free-fall nuclear bomb was adopted in service in 1955. It was developed on the basis of the prototype TX-21 "Shrimp", which was tested in March 1954 (the Castle Bravo test).

The Mk-21 reentry vehicle (RV) used with the W87 warhead was previously known as the ABRV, Advanced Ballistic Reentry Vehicle, designed by AVCO Systems Division. This RV affords the warhead greater accuracy.

Mark 21 or Mk XXI or variation, may refer to:

2024年4月18日 · The Mark 21 fuze, an integrated assembly of Sandia-designed logic and sensing devices directs the warhead to initiate firing sequences at the correct point in targeting parameters. The Mark 21 Fuze Replacement Program is a partnership between the NNSA and the U.S. Air Force.

2024年6月19日 · It will carry the future ICBM payload — the W87-1 nuclear warhead, an upgrade on the W87 carried by the operational Minuteman III ICBM Mk 21 reentry vehicle. Work is being performed in Pennsylvania and is expected to be completed by October 2026.

2019年10月17日 · The Air Force has awarded Lockheed Martin a $108 million contract for the Mk21A reentry vehicle -- a platform that's intended to deliver the W87-1 warhead from the Ground Based Strategic Deterrent system.

2024年6月18日 · Mk21A is the U.S. Air Force’s integrated reentry vehicle and the critical front-end of the service’s future intercontinental ballistic missile (ICBM) weapon system. This flight test from Vandenberg Space Force Base in California, tested Lockheed Martin’s Mk21A design components and technologies for the vehicle.