Micro Laser Plasma Thruster Technology Development

"BMDO has a critical need for advancements in propulsion to achieve major reductions in the costs of placing and maintaining payloads in desired locations. In particular, efficient launch systems for small technological payloads and advances in smallthrusters propulsion systems are needed, and these require revolutionary, new aerospace propulsion-related technologies. The micro Laser Plasma Thruster (uLPT) which Photonic Associates originated is such a technology.Our uLPT uses a cluster of diode lasers focused to a 50mm spot on the back of a transparent tape coated with a 50mm-thick carbon-containing absorbing layer. As the tape moves across the laser focus, a high-temperature jet is created on the opposite sidefrom the laser without burning through the tape. This is called "transmission mode" illumination.Under earlier Air Force funding, we developed and tested a preprototype thruster which exceeded the TechSat 21 requirement of 75mN thrust per axis. Technical issues which remain include "reflection" vs. "transmission" modes of target illumination andminimizing outgassing of ablation coatings.In this Phase I effort, we will address remaining technical issues and design a commercially viable prototype thruster to be built under Phase II. The laser-driven engine we propose will have 200¿N thrust, 30W power requirement, and total mass 0.75kg. This effort will lead to Phase II development of the first laser-driven microthruster. Its app