Proton-K Blok-D

8K82K 11S824

Mission Profile

The Proton-K Blok-D (8K82K 11S824) was a four-stage Soviet heavy-lift rocket combining the Proton-K three-stage booster with the high-energy Blok-D cryogenic upper stage for deep space and high-orbit mission delivery. 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 was used extensively for lunar, planetary, and geostationary satellite missions. First flown in March 1967, the Proton-K Blok-D launched the Zond lunar probes, Mars and Venera series planetary missions, early Salyut space station modules, and numerous geostationary communications satellites.