Space Shuttle Main Engine — The Relentless （航天飞机主发动机u2014u2014无情的）.pdfVIP

Space Shuttle Main Engine — The Relentless Pursuit of Improvement * Katherine P. Van Hooser0F NASA Marshall Space Flight Center, Huntsville, Alabama 35812 Douglas P. Bradley † 1F Pratt Whitney Rocketdyne, Canoga Park, California 91303 The Space Shuttle Main Engine (SSME) is the only reusable large liquid rocket engine ever developed. The specific impulse delivered by the staged combustion cycle, substantially higher than previous rocket engines, minimized volume and weight for the integrated vehicle. The dual pre-burner configuration permitted precise mixture ratio and thrust control while the fully redundant controller and avionics provided a very high degree of system reliability and health diagnosis. The main engine controller design was the first rocket engine application to incorporate digital processing. The engine was required to operate at a high chamber pressure to minimize engine volume and weight. Power level throttling was required to minimize structural loads on the vehicle early in flight and acceleration levels on the crew late in ascent. Fatigue capability, strength, ease of assembly