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.

Exploded diagram of the Mk21 reentry vehicle for the W87 [clarification needed] 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 ...

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).

In terms of identification, the W59 refers to the nuclear warhead manufactured, and the term Mk-5 refers to the reentry vehicle used with that specific warhead. Combined, the warhead and reentry vehicle had a width of 16.3 inches, height of 47.8 inches and weighed 550 pounds. The W59 had a yield of 1 megaton, MT.

Sep 1, 2001 · Mk-21 RV formerly known as the ABRV (Advanced Ballistic Reentry Vehicle) developed by AVCO Systems Division. Heavier, but higher accuracy and lower cost than the Mk-12A. Tests of the Mk-21's hardness to nuclear effects were conducted in 1984-86:

The W87 warhead/Mk21 reentry vehicle (RV) is the leading candidate for a single RV option for the Minuteman III ICBM. It is the most modern and safe U.S. nuclear warhead. It incorporates all...

Mk21A is an integrated reentry vehicle (RV) being designed to deploy the W87-1 warhead for the U.S. Air Force’s future Sentinel ICBM. It is an adaptation of the Mk21 reentry vehicle. The Lockheed Martin Mk21A design is maturing using advanced Digital Engineering tools, including advanced modeling and simulation.

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.

8月18号据《环球军事网》报道，美国在位于西部沙漠的桑迪试验场惊进行了最新的MK-21再入飞行器测试，据透露此次是通过模拟爆炸冲击波来检验导弹的引信装置方面的性能，检验引信装置性能也是美国战略导弹未来发展的一部分。 从网上公布的视频上来看，首先是工作人员做好了前期的准备，不久后沙漠中便传来一声巨响，片刻过后工作人员就当即冲了上去收集相关的资料，据美国对外宣布称新型的核弹头引信爆炸圆满成功。

Aug 1, 2014 · Castle Bravo was the first “dry” (solid fuel) H-bomb the US detonated, using lithium deuteride in a natural uranium tamper. It was the basis for the MK-21 bomb which went into further development beginning on March 26; by December 1955, mass production began and 275 units were built through July 1956.