Today, Proton celebrates the 45th anniversary of its first flight. Originally named UR-500, the rocket later took on the name Proton in homage of its first three payloads. Its first payload, the satellite “Proton-1,” weighed over twelve tons and was inserted into orbit at 589 km apogee, 183 km perigee, and an inclination of 63.4 degrees.

Exploratory work to create a heavy-lift launcher began the second half of 1961 under the leadership of Vladimir Chelomei. Chelomei originally designed it with the intention of creating both a powerful rocket for military payloads and a high-performance ICBM. However, the program was changed in subsequent years when the USSR formally ordered the design of the vehicle be used exclusively for launching spacecraft.

The first developed launcher was a two-stage variant of the vehicle. After its first four launches, it was decided to develop four and three stage variants, with a liftoff weight of over 700 tons. The two-stage vehicle was last flown in 1966.

March 10, 1967 marked the inaugural circumlunar capable Proton vehicle. The mission, which carried the satellite Cosmos 146 onboard, set in motion Proton’s space exploration program. Proton has launched interplanetary missions to the Moon, Venus, Mars, and Halley’s Comet. Proton has also launched the Salyut space stations, the Mir core segment and both the Zarya and Zveda modules for the International Space Station.

In July of this year, Proton completed its 24th successful consecutive launch in 24 months with the launch of the EchoStar XV satellite. With this record, Proton sets a high rate of pace and reliability. Since the beginning of 2010, Proton has already achieved seven launches, which have resulted in 8 spacecraft orbit insertions.

All commercial launches on Proton are managed by a joint Russian-American venture, International Launch Services Inc. (ILS). ILS is a U.S. company, headquartered near Washington, D.C. and has exclusive rights to market the Proton vehicle to commercial satellite operators worldwide. In 2008, Khrunichev became the majority shareholder in the company.

The first commercial launch of ILS Proton was successfully implemented on 09 April, 1996 carrying the ASTRA 1F satellite onboard. Currently the Proton has flown 358 times.