An unfired Isayev S2.720A bi-propellant regenerative thrust chamber developed for use in the second stage of the Soviet S-75M Surface to Air Missile (SAM) system and produced by the Isayev Design Bureau. This chamber burns a hypergolic mixture of triethylamine/xylidine (fuel) with nitric acid as the oxidizer and is rated at 34 KN vacuum thrust. Chamber measures 40″ tall with the nozzle having an 8.5″ diameter. All parts are numbered, with the affixed metal label reading “CZ 720 0000-0 204420.” The chamber is also bolted to a four-legged display stand with an overall height of 45″. In fine condition.
Alexei Isayev specialized in small-scale, liquid-fueled rocket engines for Soviet manned and unmanned spacecraft. From 1957 to 1967 his engines powered the rockets carrying the first artificial satellites, the first man in space, and the first unmanned probes to the Moon and Venus. At the same time, in the 1950s, he was working on engines for surface-to-air missiles (SAMs) and air-to-sea missiles. An unusual artifact of the Cold War and a reminder that the space programs were largely an offshoot of military research and development.
Terms and abbreviations used in our descriptions.