A tethered spacecraft is being developed by the Spacecraft Engineering Department to demonstrate electrodynamic propulsion in space. Electrodynamic propulsion holds the promise of limitedless propulsion for maneuvering spacecraft without using expendable fuel. Electrodynamic propulsion can enable missions not previously possible, such as drag makeup for low altitude applications, multiple maneuvers to rendezvous with and deorbit space junk and repeated traverses through low altitudes to collect science data on the ionosphere. The NRL spacecraft, TEPCE, will consist of two 1.5U CubeSats attached to each end of one kilometer of electrically conducting tether. The two Cubesats are virtually identical, housing a processor, memory, command and data handling system, RF system, an elementary attitude control and attitude determination system. Unique to TEPCE will be the electrodynamic devices for the propulsion consisting of electron emission filaments, electron collection tapes, electrically conducting tether and the tether deployment subsystem. The experiment will also carry into space several plasma experiments, the iMesa sensor developed by NRL code 7669 and dual impedence probes developed by NRL, code 6755. The plasma experiments will take multiple measurements of the electron density and electron temperature as TEPCE orbits the earth.
The development centered around CubeSats provides a low cost approach for development and enables launch opportunities through the Space Test Program (STP). TEPCE will operate between 500 and 1000 km at inclination above 35 degrees. TEPCE is projected to be completed in June of 2011 with launch as soon as possible thereafter.