Basic Research Investigations into Multimode Laser and EM Launchers for Affordable Rapid Access to Space (Volumes 1 and 2)

Abstract

This basic research effort on pulsed airbreathing/rocket laser propulsion , investigates the physics of laser energy deposition into stationary and hypersonic working Ouids, inclusive of electrical breakdown, ignition of laser-supported detonation waves (LSD}, and blast wave propagation over thruster impulsegenerating surtaces. The future application of AFOSR interest for this basic research endeavor is the laser launch of nano-and micro-satellites (i.e. , 1-1 00 kg payloads} into Low Earth Orbit (LEO), at low cost and "on-demand." The present dual-pronged, combined experimental/numerical research campaigns centered on both static and hypersonic experiments with representative 20 and 30 laser-thruster geometries, using the Lumonics TEA-622 (-200J, -1 OOns) and K922M (20-40J, -100ns) C0 2 lasers. Laser scramjet experiments were pertormed in the T3 tunnel at the Henry T. Nagamatsu Laboratory of Aerothermodynamics and Hypersonics (HTNLAH). Time-dependent surtace pressure distributions were measured over thrust-generating surtaces following laser energy deposition; delivered impulse and momentum coupling coefficients (Cm) were obtained; Schlieren moviesof the impulse generation process were recorded with a high-speed Cord in digital camera, to study the laser breakdown/ blast wave expansion process, and evolving flow field structures in both stationary and hypersonic flow. Time-resolved visualizations of inlet and absorption chamber flowfields, enabled qualitative analysis of dominant phenomena impacting laser-propulsion physics.