Russian Military spy satellite Turksat 4A launched by Proton M rocket from Baikonur Cosmodrome

Russia’s Proton-M rocket has successfully conducted a return-to-flight mission Sunday with the deployment of a military satellite for the Russian government. The mission, carrying a payload named Olimp, ends four months of downtime for Russia’s heavy-lift rocket following a launch failure in May.The Proton-M, which is the largest and most powerful rocket in Russia’s fleet, first flew in 2001 although its design is much older.

A modernised version of the earlier Proton-K, which was used from 1967 to 2012, the Proton-M can trace its lineage back to Vladimir Chelomei’s Universal Rocket concept; a planned series of missiles to provide the Soviet military with a series of similar but increasingly powerful missiles.Three of the Universal Rocket designs made it to the launch pad. The smallest, the UR-100, was the only series to see operational service as missiles. In recent years as these have been withdrawn from service decommissioned UR-100s have also spawned the Rokot and Strela carrier rockets.

The UR-200, which was larger than the UR-100, was designed to deliver warheads over longer distances, although its use was also envisioned as a carrier rocket for antisatellite weapons and as part of the fractional orbit bombardment system – whereby nuclear warheads would be placed into a low earth orbit and then deorbited onto their target during their first revolution.Despite a series of successful test flights, the R-36 was selected over the UR-200 and as a result it never entered service.

The largest missile in Universal Rocket series was the UR-500. Intended to deliver the heaviest warheads over long distances, it proved far too large to be useful as an ICBM and its first few launches were used to place 5-tonne scientific satellites into orbit. With the addition of a third stage the UR-500 was reborn as the Proton-K, then the USSR’s largest and most powerful orbital launch system.In a three stage configuration the Proton-K was used to launch some of the heaviest Soviet spacecraft into low Earth orbit – including the Salyut space stations – while most launches make use of an additional fourth stage to allow higher orbits to be reached.Today the Proton is used almost exclusively for launches to higher orbits – usually communications satellites bound for geosynchronous orbits or GLONASS navigation spacecraft destined for semi-synchronous medium Earth orbits.

All launches since 2000 have been in four-stage configurations – the last three stage launch being that of the Zvezda module of the International Space Station. The Proton-M has never flown without a fourth stage, however a three-stage configuration will be used for the launch of Nauka late next year.