Proton (UR-500, 8K82)

Historical information

Proton (formal designation: UR-500) is an expendable launch system used for both commercial and russian government space launches.

The first Proton rocket was launched in 1965 and the launch system is still in use as of 2014, which makes it one of the most successful heavy boosters in the history of spaceflight.

Like many soviet boosters, the names of recurring payloads became associated with their launchers. Thus the moniker "Proton" originates from a series of large scientific Proton satellites, which were among the rocket's first payloads. During the Cold War, it was designated the D-1/D-1e or SL-12/SL-13 by Western intelligence agencies.