Design Studies of the Advanced Technology Engine

The need was identified for a high-performance bipropellant rocket engine in the 20-kN range for use with Ariane 5, for the transfer of telecommunication satellites to geostationary orbit, and for scientific (interplanetary) missions. The concept deals with a high-performance, pump-fed storable bipropellant engine using monomethyl hydrazine and nitrogen tetroxide propellants. Its target specific impulse of 345 s is close to the theoretical maximum value possible for this propellant combination. The versatility of the advanced technology engine may be enhanced by using it in combination with a general purpose orbital propulsion module for the transfer of stacks of two or three satellites. To develop the concept in detail, design and study contracts were placed with five European propulsion companies. Engine requirements were derived from mission analyses. The studies lead to the selection of a precombustion cycle engine design with a specific impulse over 350 s, which could be developed in Europe in eight years for a cost of 123 million accounting units.