In support of designing lunar lander concepts, the propulsion team at NASA Marshall Space Flight Center and the Johns Hopkins University Applied Physics Laboratory, with participation from industry, conducted a series of trade studies on propulsion concepts with an emphasis on light-weight and technologically-mature components. The results suggested that a high-pressure propulsion system may offer some benefits in weight savings and system packaging. As part of the propulsion system, a solid rocket motor was selected to provide a large impulse to reduce the spacecraft’s velocity prior to the lunar descent. In parallel to this study effort, the Robotic Lunar Lander Development Project collaborated with engineers from White Sands Test Facility and Pratt & Whitney Rocketdyne to perform a series of hot-fire tests on two high thrust-to-weight thrusters – a 100-pound-class for lunar descent and a 5-pound-class for attitude control. The team used a lunar mission profile during the test of the miniaturized thrusters to assess the capability of these thruster technologies for possible use on future NASA spacecraft.
The test program fully accomplished its objectives, including evaluation of combustion stability, engine efficiency, and the ability of the thruster to perform the mission profile and a long-duration, steady-state burn at full power. The test results will allow the Robotic Lander Project to move forward with robotic lander designs using advanced propulsion technology.