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TEPCE Tether Electrodynamic Propulsion CubeSat Experiment |
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TEPCE is a Naval Research Lab "triple cubesat" electrodynamic tether experiment planned for launch in 2011. TAI is providing hardware and mission design and analysis support and some components to NRL. TEPCE uses two nearly identical endmasses with a stacer spring between them. The stacer will energetically separate the endmasses. This will start deployment of a 1 km x 2x0.2mm braided-tape conducting tether stowed around the stacer. Passive braking will be used to reduce speed and hence recoil at the end of deployment. TEPCE will use carpenters' tape electron collectors plus hot-wire electron emitters at each end, so it will be able to drive an electrodynamic current in either direction. It will be able to climb or descend several km/day, change its libration state, slowly change orbit plane, and actively maneuver to avoid other tracked objects. |
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EDDE ElectroDynamic Debris Eliminator |
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EDDE is an operational electrodynamic vehicle proposed by Jerome Pearson of STAR Technology and Research. STAR and TAI have worked on it under AFRL, NASA, NIAC, and DARPA funding, and are about to receive additional funding from DARPA. EDDE spins like a propeller to stabilize itself. The spin also lets EDDE push and pull against the earth's magnetic field as desired, allowing controlled changes in all 6 orbit elements. EDDE uses a 30mm wide reinforced aluminum-foil tape as a full-length 10 km electron collector and conductor, to improve electron collection at high altitudes. EDDE's solar arrays are distributed along its length. They serve as "electron pumping stations" that limit peak voltages relative to the local plasma. They also allow prompt detection and active quenching of arcs triggered by micrometeoroid impact on negatively-biased parts of EDDE, to prevent TSS-like failures due to sustained arcing. Like TEPCE, EDDE can flow current in either direction, but EDDE will use hollow cathodes as electron emitters, to allow multi-amp currents. EDDE will be able to capture objects in expendable spinning nets deployed from either end, and drag them either down into short-lived orbits, or to facilities that might recycle much of the ~2100 tons of debris now in low earth orbit. Each EDDE weighs ~100 kg and should be able to handle ~25 tons of LEO debris per year. So a dozen EDDEs may be able to clean up most of the 2100 tons of debris in LEO within ~7 years. Thereafter a few EDDEs can stay in orbit to remove new spent stages and failed satellites on demand, providing a new option for complying with the "25-year rule." |
TEPCE integrated prior to deployment test.
TEPCE during free fall deployment test.
EDDE components.