Accession Number : ADA187336

Title :   Advanced Energy Conversion Concept for Beamed-Energy Propulsion.

Descriptive Note : Final rept. Sep 84-Nov 86,

Corporate Author : RENSSELAER POLYTECHNIC INST TROY NY DEPT OF MECHANICAL ENGINEERING AERONAUTIC AL ENGINEERING AND MECHANICS

Personal Author(s) : Myrabo, Leik N

PDF Url : ADA187336

Report Date : 21 Aug 1987

Pagination or Media Count : 197

Abstract : The principal objective of this study was to perform basic research investigations into an innovative power conversion concept for trans atmospheric, beamed energy propulsion: a new class of External Surface Impulse (ESI) thrusters. This advanced thruster principle could be used for atmospheric VTOL, high acceleration, and lateral flight (e.g., short-term cruise ) propulsion of Single-Stage-To-Orbit (SSTO) beam-powered shuttlecraft of the next century. Three classes of ESI thrusters were initially examined: 1) simple thermal, 2) electrostatic and 3) electromagnetic. Beam power wavelengths from 10cm (microwave) to 0.3um (laser) were considered. The subsequent research effort concentrated on the simple thermal repetitively-pulsed ESI thrusters, energized with laser power and using air as the working fluid. Laser frequencies were selected because of the relative wealth of experimental data and theoretical research on laser impulse coupling which exists in the literature. The first year analytical effort has proven conclusively that such an engine can deliver high levels of thrust-to-beam-power at liftoff (e.g., at least an order-of-magnitude greater than beam-powered hydrogen-fueled rockets), with infinite specific impulse (decreased only, perhaps, by ablation of the thruster surface). Later along an orbital trajectory, the primary propulsion function would transition to other modes; upon leaving the atmosphere, the SSTO vehicle would continue in a pure rocket mode with a specific impulse (I sp) of 1000 seconds or more. Keywords: Advanced airbreathing propulsion, Beamed energy propulsion, External radiation heated (EH) thruster.

Descriptors :   *ENERGY, *LASERS, *PROPULSION SYSTEMS, *THRUSTERS, ABLATION, AIR BREATHING ENGINES, CONVERSION, COUPLING(INTERACTION), ENERGY CONVERSION, EXPERIMENTAL DATA, EXTERNAL, FLUIDS, FREQUENCY, ORBITS, POWER, PULSES, PURITY, RADIATION, ROCKETS, SHORT RANGE(TIME), SPECIFIC IMPULSE, STAGING, SURFACES, TRAJECTORIES

Subject Categories : Lasers and Masers
      Electromagnetic Pulses
      Nuclear Propulsion

Distribution Statement : APPROVED FOR PUBLIC RELEASE