Aerojet, a GenCorp (NYSE: GY) company, has successfully completed a hot-fire testing program of NASA's Orion Crew Module's 160 lb. thrust mono-propellant engine. Test program objectives were met by demonstrating pulse mode operation of the engine at expected Orion flight conditions. The altitude/pulse mode hot fire test program consisted of 87 engine starts (exceeding the specification requirement), 2,118 engine pulses (exceeding the previous qualification and nearly three times the specification requirement), and more than 400 lbs. of propellant throughput (approximately two and half times the specification requirement). The testing concluded not only with the objectives met but with life remaining on the engine, indicating that the MR-104G, with upgraded thrust, will meet the required Orion pulse mode operating conditions.