Monopropellant Exhaust Contamination Investigation

Abstract : This report presents the results of the Monopropellant Attitude Control Rocket (ACR) exhaust contamination investigation. The purpose of this effort was to determine ACR engine plume effects on vehicle space-borne equipment, i.e., thermal control paint, solar cells and optics. Plume impingement tests were conducted at an altitude of 400,000 feet, using a 25-lb- thrust monopropellant attitude-control rocket engine. The propellant was hydrazine (N2H4) and the ignition source was Shell 405 catalyst. A series of 200 firings were conducted at each test position at an engine pulse width of 200 milliseconds. The analysis of the test data revealed that the monopropellant ACR exhaust plume had little or no effect on the operating characteristics of the space-borne equipment involved in the test program. Furthermore, the monopropellant exhaust plume concerning contamination is relatively clean compared to a bipropellant ACR plume using N2O4/A-50 and/or N2O4/MMH. This comparison is based on past bipropellant plume contamination test results.