NPO Molniya, Antonov, and TsAGI proposed a spaceplane demonstrator project to the European Space Agency in 1993-1994 under the RADEM project. This would be a scaled-back version of the cancelled MAKS spaceplane using existing rocket engines. An unmanned prototype of the MAKS would be fitted out with RD-120 Lox/Kerosene engines. Launched from atop the An-225, the MAKS-D would reach an altitude of 80 to 90 km and a speed of Mach 14 to 15.

The ES experimental spacecraft would have a launch mass of 56 tonnes, including 45 tonnes of propellant. It would fly at hypersonic speed out to a range of 1500 km, then return to an automatic landing at its launching base. Three variants were proposed:

• Basic variant. Purpose of the flight tests would be to prove MAKS-M / I-HOTOL flight algorithms, materials, and engine reusability. 38.0 m length x 24.0 m wingspan

• Basic variant modified for scramjet flight tests

• Orbital vehicle with 2 tonnes payload. For the orbital vehicle the MAKS-D served as the first stage of the booster. It would release the RS rocket stage, equipped with a European HM-7B Lox/LH2 engine. The rocket stage engine would ignite five seconds after release of the aircraft from the An-225 transport and work in tandem with the RD-120 installed on MAKS-D. Following exhaustion of main stage propellants the MAKS would release the rocket stage, which would continue on to orbit. This scheme was analogous to NASA's early X-34 concepts.

LEO Payload: 2,000 kg. to: 200 km Orbit. at: 51.0 degrees. Total Mass: 185,000 kg.

• RADEM project

  NPO Molniya, Antonov, and TsAGI proposed a spaceplane demonstrator project to the European Space Agency in 1993-1994 under the RADEM project. This would be a scaled-back version of the cancelled MAKS spaceplane using existing rocket engines.

• 458 - Lozinskiy, Need title - Air space vehicles, .