Apollo 15 to Apollo 12, and since Apollo 11's backup crew had been designated for Apollo 13 (which did not land on the Moon), they were the first Apollo crew for a successful lunar landing mission to have backed up another such mission. Having had the opportunity to familiarize themselves with the Apollo spacecraft, they could devote more of their training time as prime crew for Apollo 15 to geology and sampling techniques. The astronauts at NASA who were scientists, such as geologist Harrison Schmitt, pushed though the early Apollo missions for a greater place for science as part of the mission,
Apollo 5 Apollo 5 Apollo 5 (also known as AS-204), was the first unmanned flight of the lunar module (LM), which would later carry astronauts to the lunar surface. It lifted off on January 22, 1968, with a Saturn IB rocket on an Earth-orbital flight. The Apollo 5 mission tested the lunar module in a space environment, in particular its descent and ascent engine systems, and its ability to separate the ascent and descent stages. The descent engine would become the first throttleable rocket engine fired in space. The mission also performed a simulation of a landing abort, in which the ascent