In the late 1990's the Russian space industry undertook the Orel programme to evaluate technology for future launch vehicles. The goals included evaluation of possible concepts for a future Russian launcher, reusable launch vehicle key technology research and analysis of "X-vehicle" flight demonstrators for technology validation. One preferred near-term configuration was this semi-reusable vertical takeoff/horizontal landing two stage launch vehicle. It would use a flyback booster, expendable second stage, and a small manned spaceplane. This was preferred to the Orel V3, which was essentially the earlier MMKS/OK-M1 system with a flyback booster, expendable core tank, and small spaceplane with recoverable main engines.
LEO Payload: 10,900 kg. to: 200 km Orbit. at: 51.0 degrees. Liftoff Thrust: 825,000 kgf. Total Mass: 550,000 kg. Core Diameter: 22.8 m. Total Length: 83.0 m.