Apollo 15 15 separated from the booster, the S-IVB maneuvered away, and would impact the Moon about an hour after the crewed spacecraft entered lunar orbit, though due to an error the impact was away from the intended target. The booster's impact was detected by the seismometers left on the Moon by Apollo 12 and Apollo 14, providing useful scientific data. There was a malfunctioning light on the craft's service propulsion system (SPS); after considerable troubleshooting, the astronauts did a test burn of the system that also served as a midcourse correction. This occurred about 028:40:00 into the mission. Fearing that the
Apollo spacecraft feasibility study a special symposium of the American Astronautical Society in Denver, Colorado. The Martin Company spent about $3 million, employing almost 300 persons for the better part of the six-month term, to produce the most elaborate study of the three, not only following all the Space Task Group guidelines, but also going far beyond in systems analysis. The complete proposal consisted of 9,000 pages. Focusing on versatility, flexibility, safety margins, and growth, this was the only study that detailed the progression of steps from lunar orbiting to lunar landing. Martin's spacecraft would have been similar to the Apollo spacecraft that ultimately