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 15 Apollo 15 Apollo 15 was the ninth manned mission in the United States' Apollo program, the fourth to land on the Moon, and the eighth successful manned mission. It was the first of what were termed "J missions", long stays on the Moon, with a greater focus on science than had been possible on previous missions. It was also the first mission on which the Lunar Roving Vehicle was used. A recording of the launch was included in the Sounds of Earth carried by the "Voyager 1" and "Voyager 2" space probes. The mission began on July 26, 1971, and