Proton-K Blok DM

8K82K Blok DM 11S86

Mission Profile

The Proton-K Blok DM (8K82K Blok DM, 11S86) was a four-stage Soviet/Russian heavy-lift launch vehicle in the Proton family, pairing the three-stage Proton-K with a Blok DM restartable upper stage for geostationary and interplanetary missions. Standing 55.4 m tall with a 7.4 m diameter and a liftoff mass of 705 tonnes, it generated 9,870 kN of liftoff thrust and could deliver 5,600 kg to geostationary transfer orbit. First flying in March 1974, the Proton-K Blok DM launched Glonass navigation, Raduga communications, and Ekran direct-broadcast television satellites throughout a decades-long career.