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.
The mission began on July 26, 1971, and ended on August 7. At the time, NASA called it the most successful manned flight ever achieved.