The Proton has a long and distinguished history, with a record that includes a number of significant firsts. Its official status as an ILS launch vehicle was solidified on April 6, 1996, when Proton's first commercial flight lofted the Astra 1F satellite in to orbit.

 

The first test launch of the original two-stage Proton took place in July 1965, when it was used to launch the four Proton satellites for which the vehicle was named. Last flown in 1966, the two-stage Proton was succeeded by the three-stage Proton K and the four-stage Proton K/Block DM launch vehicles.

 

Since the mid-1960's, Proton has served as the primary heavy-lift launch vehicle for Russian unmanned space programs, orbiting the Salyut series space stations and the MIR space station modules, as well as two of the first elements of the International Space Station, the Zarya and Zvesda modules.

 

The four-stage Proton has launched the Ekran, Raduga and Gorizont series of geostationary communications satellites, as well as the Zond, Luna, Venera, Mars, Vega, and Phobos interplanetary exploration spacecraft. These missions produced the first samples of the lunar surface to be returned by an unmanned spacecraft, and the first soft landing on the surface of Venus.

 

Utilizing an evolutionary approach, Khrunichev's "modernized" version of the Proton -- Proton/Breeze M -- draws 77% of it components from flight-proven heritage systems, with the Proton M and Breeze M being comprised of 84% and 65% heritage systems, respectively. It provides a 20% increase in performance, greater payload fairing usable volume and increased payload structural capacity.

 

The upgraded first stage engines were phased in over a span of three years, while the Breeze M upper stage is based on the propulsion system and core module of the Breeze KM unit currently flying on the Rockot lightweight class launch vehicle. By gradually eliminating risk, the Proton launch vehicle family has become the principal heavy launcher in the Russian space program and one of the premier launch vehicles in the world.