Molniya (rocket)

The Molniya, GRAU index 8K78, was a four-stage Soviet launch vehicle built as a modification of the R-7 Semyorka rocket. It came out of a crash program of the Korolev Bureau to develop a booster for launching planetary probes: a larger third stage was added, together with a fourth stage, the Blok L, designed to fire in orbit and send the payload out of low Earth orbit, replacing the inaccurate direct ascent used by the first generation of Luna probes on the 8K72. The core and strap-on boosters carried the uprated 8D74K first stage engines. The first Blok I third stage was prone to vibration and pump cavitation and was redesigned, the improved version first flying on 11 November 1963, and an uprated 8K78M was introduced in 1965 while the original 8K78 kept flying into 1967. Besides the Venera probes it carried, the rocket took its name from the many Molniya communications satellites it launched. It stood 43.44 metres tall, had a launch mass of 305,000 kilograms, flew 40 times from Baikonur and Plesetsk and is retired.