Laser Plasma Microthruster Performance Evaluation

The micro laser plasma thruster (μLPT) is a sub‐kilogram thruster that is capable of meeting the Air Force requirements for the Attitude Control System on a 100‐kg class small satellite. The μLPT uses one or more 4W diode lasers to ablate a solid fuel, producing a jet of hot gas or plasma which creates thrust with a high thrust/power ratio. A pre‐prototype continuous thrust experiment has been constructed and tested. The continuous thrust experiment uses a 505 mm long continuous loop fuel tape, which consists of a black laser‐absorbing fuel material on a transparent plastic substrate. When the laser is operated continuously, the exhaust plume and thrust vector are steered in the direction of the tape motion. Thrust steering can be avoided by pulsing the laser. A torsion pendulum thrust stand has been constructed and calibrated. Many fuel materials and substrates have been tested. Best performance from a non‐energetic fuel material was obtained with black polyvinyl chloride (PVC), which produced an average...