Reusable Orbital Transfer Vehicle Applications of an Integrated Solar Upper Stage

Abstract

There has been resurgent interest in the development of a reusable orbit transfer vehicle, based in lowEarth-orbit, for satellite placement, repositioning, recovery, and control. An integrated solar upper-stage system is examined for several near-Earth applications, including low-Earth to geosynchronous to lowEarth orbit ferrying. An integrated solar upper stage (a solar thermal power and propulsion system) permits rapid access to high orbits because of its moderate thrust levels (tens to hundreds of pounds) at specific impulses approaching 900 s, intermediate between high-performance chemical propulsion and electrical propulsion systems. An integrated solar upper-stage reusable orbit transfer vehicle can be used in two novel modes: 1) Drag return, in which large, rigid solar concentrators provide an aeroassist capability lowering total delta-V requirements; and 2) a hybridized integrated solar upper stage, coupled with and providing power to a xenon ion thruster, allowing more efficient maneuvers in nontime critical applications.