Second Generation Engines

Asteroid Deflection

Terrestrial Applications

Hybrid Reusable Launch Vehicle

Another way to limit the kinetic output is to use the technology in a lift engine where the high specific thrust is used only to counteract gravity. Any acceleration of the vehicle itself would be by conventional propulsion.

An early design study has shown that a 260 tonne hybrid reusable launch vehicle employing four 22 kW lift engines could launch 20 tonnes of payload into LEO. A rocket engine of 1 tonne thrust would be used for ascent, whilst a 50 tonne thrust rocket engine would be used to attain orbital velocity. High temperature superconducting materials would be used in the lift engines, which would be cooled by a total loss system, employing the cryogenic propellants of the rocket engines.

The mean ascent velocity would be 50m/s with orbit engine operation delayed until vacuum has been reached. The vehicle shape can therefore be optimised for re-entry rather than launch. A truncated cone shape is proposed, (similar to the Apollo command module), with a base diameter of 18m and an overall height of 14m. Conventional aerobraking would be used during re-entry followed by vertical landing using the lift engines and the ascent engine.