Proton-K Blok D-2

8K82K Blok D-2 11S824M

Mission Profile

The Proton-K Blok D-2 (8K82K Blok D-2, 11S824M) was a four-stage Soviet/Russian heavy-lift launch vehicle in the Proton family, pairing the Proton-K with a Blok D-2 upper stage optimised for interplanetary mission profiles. 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 5,500 kg to geostationary transfer orbit. First flying in July 1988, the Proton-K Blok D-2 launched the Phobos Mars mission spacecraft, designed for demanding deep-space trajectory insertion.