No other launcher has played as many roles in the Russian space program as has the UR-500 rocket, known today as Proton. Conceived at the dawn of the space race as a "super-size" ICBM, the UR-500 became a major player in the race to the Moon in the mid-1960s. In the 1970s and 1980s, the four-stage version of the launch vehicle launched Soviet planetary probes toward the Moon, Mars and Venus and allowed the Soviet Union to place satellites into geostationary orbit. At the same time, three-stage Protons launched all Soviet space stations, as well as heavy transport ships and modules to expand and resupply them in space. In the 1990s, the Proton became the workhorse of Russia's commercial launch business.