Soyuz-3
 
 


The most powerful  Soyuz-3 was proposed specifically to carry the Kliper reusable orbiter into orbit.
The Soyuz-3 concept had surfaced in 2005. Soyuz's promising career in the European commercial launcher fleet, prompted the RKK Energia, Russia's prime developer of the manned spacecraft, to consider launching its next-generation Kliper spacecraft on the "pumped-up" version of the Soyuz rocket. Several other previous, less ambitious upgrade projects -- Yamal, Aurora and Onega -- up to now had a chance to leave a drawing board due to lack of funding.

For its potential role as the launcher of the Kliper, Soyuz-3 competed with two other major candidates -- Ukrainian Zenit and Angara 3-I -- developed by Khrunichev Enterprise in Moscow. Unlike the Zenit, which has been in service since the 1980s, and Angara, whose development inched ahead since mid-1990s, the Soyuz-3 had to be developed from scratch, even with all its extensive heritage technology embedded into its design.
The Soyuz-3 apparently borrowed body dimensions for the booster and 1st stages from the Aurora project. The top section of the 1st stage (also known as core or sustainer stage) would have a cylindrical shape with the constant diameter, as oppose to conical shape of its predecessors. The Soyuz-3 would carry NK-33-1 engine.
The first stage, traditionally comprised of four conical strap-on boosters, would be equipped with a modified version of the RD-120.10F engine.
Finally, the biggest change would come in the third stage, which should be developed from scratch and equipped with four RD-0146E engines, burning cryogenically cooled liquid oxygen and liquid hydrogen. The basic concept of the engine was also intended for upper stage of the Angara launch vehicle.