New Satellite Propulsion System Has Mass Below 100 Grams (0.22 pounds).
AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
Pagination or Media Count:
There is an increased need for propulsive microsatellites to support a range of future specialized Air Force and NASA missions. In response to this need, the Air Force Research Laboratorys AFRL Spacecraft Propulsion unit at Edwards AFB, CA, has developed the 100-gram Micro Pulsed Plasma Thruster MicroPPT, a simple, miniaturized propulsion device designed for propulsive attitude control on present 100-kilogram small satellites, and for stationkeeping and primary propulsion on next-generation 25-kilogram-class microsatellites. The primary features of the MicroPPT are the use of a solid inert propellant Teflon, expected high-Isp due to the use of electromagnetic acceleration, and a simple, lightweight design based largely on commercial, flight-qualified electronic components. For 100-kilogram-class small satellites a set of 4 MicroPPTs, each designed with 3 selectable thrust directions, can provide full spacecraft attitude control, yet require only 110th the mass of standard torque rods and reaction wheels. The MicroPPT was invented in 1997 and it is currently slated for flight as a micropropulsion demonstration aboard the AFRL TechSat21, scheduled for launch in 2004. The rapid advancement of the MicroPPT from invention to flight manifestation is indicative of the inherent simplicity of the device, and of the importance AFRL is placing on the development of microsatellite enabling technologies. This paper describes the design and functioning of the MicroPPT, including its propellant assembly, electronic firing mechanism, self-consuming satellite design, and cable guns. Laboratory testing, modeling, and analysis have led to MicroPPT assembly designs that demonstrate long lifetimes without char formation. MicroPPT lifetime is now limited only by the amount of available propellant and has demonstrated over 1 million discharges without failure. 4 figures, 8 refs.
- Electric and Ion Propulsion
- Solid Rocket Propellants