Launched in 1966, it was part of the Lunar Orbiter program designed to photograph the Moon's surface to identify potential landing sites for the Apollo missions. Lunar Orbiter 1 took over 200 high-resolution photographs covering 99% of the Moon's surface.

While other probes like the Soviet Luna 3 took earlier images of the Moon, Lunar Orbiter 1 provided the first extensive, detailed mapping of the lunar surface, paving the way for human exploration.