Radiation Augmented Propulsion Feasibility.

Gas phase absorption of solar radiation has been suggested as an energy source to power space propulsion systems. The absorbing gas could be an expendable propellant or could be used in a closed cycle, exchanging heat with an expendable propellant. This study was conducted in order to develop basic data and understanding useful for the evaluation of such a system with the absorbing gas being a halogen or an interhalogen. Experiments and analysis were conducted to characterize the absorption of ultraviolet and visible radiation and subsequent energy release in chlorine gas, iodine monochloride vapor, and mixtures of hydrogen gas and chlorine gas. Xenon flashlamps were used to provide the radiation. Measurements included lamp electrical and optical characteristics, light energy absorbed, pressure rise in the closed reactor and reactants remaining after the reaction. Analysis included detailed kinetic modeling of the single shot experiments.