SDIO electric propulsion objectives and programs

Abstract

Mission studies reveal that Earth orbit transfer missions, station keeping, and elusive maneuvering missions benefit from the application of efficient electric propulsion (EP) systems. The Dual Mode of utilizing significant on-board power (i.e., > 10 kW) for the main mission coupled to electric propulsion for orbit transfer and maneuvering is creating new EP opportunities. Space experiments involving EP are being planned around two state-of-the-art thruster types: arcjet and ion. Long term research on high thrust-density ion propulsion is aimed at 5 to 25 kW operation in the 5000 s specific impulse (L-) range. Shorter term research is focused on the NH3 arcjet for the SP-100 flight mission. Demonstrated 30 kW arq'et sustained life (versus <3 kW demonstrated sustained life for the ion engine) and the arcjets's inherent simplicity offer low risk and minimum cost for the SP 100 flight demonstration objectives. In addition, solar power flight experiments offer near term opportunities to acquire flight experience on these nearly-developed high power arcjet systems.

Performance enhancement using power beaming for electric propulsion Earth orbital transporters

“…Arcjet performance characteristics indicate a specific impulse of 1050 s, thruster efficiency of 45%, and specific mass of 0.13 kg,/k\Ve. The performance criteria given are based on a 30-kVV ammonia arcjet [1]. The arcjet requires about 120 V direct current (DC) during operation.…”