An all-electronic two-way transportation system between LEO and GEO combining high specific impulse electric propulsion with power supplied from the earth via a microwave beam link

Abstract

This paper describes an all-electronic generic space transportation system between low-Earth orbit and geostationary orbit and it examines how the system could benefit the geostationary communication satellite system by reducing the cost of transport of satellites to GEO and by the retrieval of satellites to low-Earth orbit. The two way transportation system is made possible by electric propulsion. The power for the electric propulsion system is transported directly from prime power sourceson the Earth to the orbital transfer vehicle via a microwave beam . The microwave beams are electronically steerable and originate on the Earth's equator so that they can contact the orbital transfer vehicle each time it orbits the Earth in the equatorial plane. The microwave beams are captured by non-directive and low specific mass rectennas aboard the vehicle and are instantly converted with over 80% efficiency into DC power for direct use by the ion thrusters. The composition, performance, and cost of such systems are examined in the paper. The issue of the potential microwave interference of the transportation system with communication satellites is also examined. I. INTRODUCTION The high cost of space transportation has always been an issue in placing communication satellites into geostationary orbit. The high cost of space transportation hasalso been an issue in many other uses of space. It was recognized in the DOEINASA study of the Solar Power Satellite. It was recently defined as a major issue in the SEI or space exploration initiative. Therefore the high cost of space transportation is a generic issue which, if solved, would greatly benefit many space applications including those satellite communication systems which depend upon geostationary orbit. It would be hoped that a solution of the transportation issue which this paper addresses would make it possible not only to transport communication satellites to geostationary orbit at a much reduced cost, but also to bring back spent satellites to low-Earth orbit for refurbishing or to be burned up in the Earth's atmosphere, thus resolving an increasingly important issue as the debris problem increases in that orbit with the passage of time. For purposes of discussion, it is noted that space transportation can be divided up into two broad categories. The first category is the transport of the mass represented by space vehicles, propellant, personnel, life support, etc. from the Earth to low- Earth orbit. The second is transportation beyond low-Earth orbit into higher altitude orbits and to outer space. Currently chemical propulsion is used for