Late in the evening on July 6, a new Mk-21A intercontinental ballistic missile (ICBM) was tested at the US Space Force Vandenberg Base in California. Eleven minutes after launch, the rocket exploded. A fire started at the cosmodrome, which was extinguished a few hours later. The wreckage was found in the immediate vicinity of the launch pad.
The launch of the rocket, which is also referred to in Pentagon documents as the Minotaur II, was carried out with the aim of testing the carrier and technologies used in the payload in real flight conditions. A second prototype is currently being assembled at the Lockheed Martin factory, with testing scheduled for the second quarter of 2023.
The results of the work on the modernization of the Mk-21 are supposed to be used in the program for the creation of a new strategic missile LGM-35A Sentinel ("Guardian"), which should replace the LGM-30 Minuteman III. Sentinel is being developed by Northrop Grumman. She received the corresponding order in 2020. It is planned to spend more than $13 billion on research and development until 2025. But in general, the entire program, together with production, modernization of mines and deployment of missiles, will cost the US budget about $ 95 billion.
Minuteman III was adopted in the 70s of the last century. Since then, ICBMs have been repeatedly upgraded: electronics have been improved, warheads have been replaced, and the composition of the fuel has been adjusted. In the end, she grew up to Minotaur II (Mk-21A). What improvements have been made by American designers is still unknown. The maximum flight range of the third Minuteman upgrade (M-21) reaches 13 thousand kilometers. Its warhead can accommodate three charges. In total, about 450 missiles are in service with the United States today. Everything is planned to be replaced by Guardians. The Minotaur II appears to be used as a test platform, or as a last resort, as a temporary solution.