A competition to develop a successor to the Proton launch vehicle was underway during most of 1993-1994. The primary contenders were the proposed Energiya-M launch vehicle, already under development for several years, and a new design named Angara. With the cancellation of the Buran space shuttle program and the deferment of government sponsored super-heavy LEO and GEO spacecraft, the original 100-metric-ton-class Energiya launch vehicle program was halted, and efforts to develop the Energlya-M launch vehicle were redoubled.
Energiya-M would employ two standard Energiya strap-on boosters with one 11D520 (RD-170) engine each and a shorter central stage with only one 11 D122 (RD-0120) engine. Upper stages and payloads would be stacked above the central stage within a large shroud. The Energiya-M could orbit LEO payloads of up to 35 metric tons or, using one of three upper stages, could provide GEO capabilities of 3.0, 4.5, or 7.0 metric tons, respectively (References 287-294).
RKK Energiya's Energiya-M ultimately lost to Khrunichev's Angara launch vehicle. The odd-looking Angara, which could begin operations between 2000 and 2005, will have a LEO payload capacity of 26 metric tons, slightly more than the forthcoming Proton-KM. More importantly, Angara will consist of a liquid oxygen/kerosene first stage and a liquid oxygen/liquid hydrogen second stage, thereby avoiding the environmental concerns of Proton's hypergolic propellants. Angara's unusual configuration will also allow it to use the Zenit launch facilities now under construction at the Plesetsk Cosmodrome. No plans have been made to fly Angara from Baikonur, but eventually the launch vehicle could take advantage of the lower latitude (compared to Plesetsk) complexes at Svobodnyy. With an additional liquid oxygen/liquid hydrogen upperstage, Angara could place 4.5-metric-ton payloads into GEO, even from Plesetsk. Later, Angara's first stage may be made reusable (References 295-300).In mid-1999 The American aerospace corporation Lockheed Martin entered into an agreement with the Russian Khrunichev Space Research-And-Production Center, providing investments of $68 million for the development by Russia of the new family of Angara rockets for commercial launches. The "Angara" family of rockets will include light, medium and heavy models. By the end of 1999 the "Angara" carrier-rocket had evolved into three types of rockets in the "Angara" family. The first one is a light rocket with a payload capacity of up to 2 tons, a rocket meant for putting into orbit small telecommunications satellites. The second rocket is capable of taking off with twice payload that is 4 tons. And the third rocket with a payload of 20 tons is expected to replace the "Proton" carrier that's normally launched from the Baikonour cosmodrome in Kazakhstan. The most high-power "Angara" missile will have higher carrying capacity than the "Proton" -- it will be able to deliver to a geostationary orbit a payload of 6 tons, and to lower orbits - payloads up to 30 tons. This marked the first time a Western company had agreed to pay for the right to promote in the international market Russian space launchers, which currently exist only in the designers' drawings. The first "Angara" light booster launching was scheduled for the end of 2001, and as many as 20 more are scheduled by 2005.