Proton-K Blok DM-2

8K82K Blok DM-2 11S861

Mission Profile

The Proton-K Blok DM-2 (8K82K 11S861) was a four-stage Soviet heavy-lift launch vehicle combining the Proton-K three-stage booster with the upgraded and more reliable Blok DM-2 restartable upper stage, optimized for precise geostationary satellite orbit insertion. Standing 55.4 m tall with a 7.4 m diameter and a liftoff mass of 705 tonnes, it generated 9,870 kN of thrust from its six first-stage RD-253 engines. First flying in October 1982, the Proton-K Blok DM-2 became the workhorse configuration for Soviet and Russian commercial geostationary satellite launches throughout the 1980s and 1990s.