Propulsive Small Expendable Deployer System (ProSEDS)

Space Transportation Directorate, National Aeronautics and Space Administration, Marshall Space Flight Center,AL 35812, 256-544-2486, leslie.curtis@msfc.nasa.gov; 256-544-0614, les.johnson@msfc.nasa.govAbstract. The Propulsive Small Expendable Deployer System (ProSEDS) space experiment will demonstrate the use of anelectrodynamic tether propulsion system to generate thrust in space by decreasing the orbital altitude of a Delta IIExpendable Launch Vehicle second stage. ProSEDS, which is planned on an Air Force GPS Satellite replacement missionin June 2002, will use the flight proven Small Expendable Deployer System (SEDS) to deploy a tether (5 km bare wire plus10 km non-conducting Dyneema) from a Delta II second stage to achieve --q3.4Ndrag thrust. ProSEDS will utilize thetether-generated current to provide limited spacecraft power. The ProSEDS instrumentation includes Langmuir probes andDifferential Ion Flux Probes, which will determine the characteristics of the ambient ionospheric plasma. Two GlobalPositioning System (GPS) receivers will be used (one on the Delta and one on the endmass) to help determine tetherdynamics and to limit transmitter operations to occasions when the spacecraft is over selected ground stations. The flightexperiment is a precursor to the more ambitious electrodynamic tether upper stage demonstration mission, which will becapable of orbit raising, lowering and inclination changes-all using electrodynamic thrust. An immediate application ofProSEDS technology is for the removal of spent satellites for orbital debris mitigation. In addition to the use of thistechnology to provide orbit transfer and debris mitigation it may also be an attractive option for future missions to Jupiterand any other planetary body with a magnetosphere.