Pulsed Laser Propulsion.

Experiments have been performed to assess the performance of a rocket that is propelled by the absorption of radiant energy from a remotely stationed, repetitively pulsed laser. A fluid mechanical model was developed for a conical nozzle to predict the necessary laser parameters for high specific impulse performance. Experiments using pulsed CO2 TEA lasers were performed with conical and parabolic nozzles. At one atmosphere background pressure a maximum specific impulse of 900 or - 400 s was obtained with an energy conversion efficiency exhaust energylaser energy of 50. At .001 atmospheric background pressure, a specific impulse of 450 or - 50 s was obtained with a self focusing parabolic nozzle and argon propellant and 1000 or - 100 s for hydrogen. Scaling laws for high thrust - high specific impulse rocket systems are discussed. Author