Solar Electric Propulsion (SEP) when used for station keeping and final orbit insertion has been shown to increase a geostationary satellite's payload when launched by existing expendable launch vehicles. In the case of reusable launch vehicles or expendable launch vehicles where an upper stage is an expensive option, this methodology can be modified by using the existing on-board apogee chemical system to perform a perigee burn and then letting the electric propulsion system complete the transfer to geostationary orbit. The elimination of upper stages using on-board chemical and electric propulsion systems was thus examined for GEO spacecraft. Launch vehicle step-down from an Atlas IIAR to a Delta 7920 (no upper stage) was achieved using expanded on-board chemical tanks, 40 kW payload power for electric propulsion, and a 60 day elliptical to GEO SEP orbit insertion. Optimal combined chemical and electric trajectories were found using SEPSPOT. While Hall and ion thrusters provided launch vehicle step-down and even more payload for longer insertion times, NH3 arcjets had insufficient performance to allow launch vehicle step-down. Degradation levels were only 5% to 7% for launch step-down cases using advanced solar arrays. Results were parameterized to allow comparisons for future reusable launch vehicles. Results showed that for an 8 W/kg initial power/launch mass power density spacecraft, 50% to 100% more payload can be launched using this method.
Advanced Electric Propulsion for RLV Launched Geosynchronous Spacecraft
1999
14 pages
Report
No indication
English
Electric & Ion Propulsion , Space Launch Vehicles & Support Equipment , Electric propulsion , Propulsion system configurations , Propulsion system performance , Spacecraft propulsion , Reusable launch vehicles , Geosynchronous orbits , Synchronous platforms , Synchronous satellites , Transfer orbits , Spacecraft launching , Orbit insertion , Solar arrays , Stationkeeping , Mission planning
Advanced Electric Propulsion for RLV Launched Geosynchronous Spacecraft
British Library Conference Proceedings | 1999
|