Lunar Orbiter probes

Lunar Orbiter probes

A series of five US space probes used for photographic reconnaissance of the Apollo landing sites (Lunar Orbiters 1, 2, and 3) and global mapping (4 and 5) of the Moon from equatorial and polar orbits respectively. The probes were launched between Aug. 1966 and Aug. 1967. Each spacecraft was equipped with medium- and high-resolution cameras, the films from which were scanned in strips for transmission back to Earth. Satellite tracking resulted in the discovery of mascons. The spacecraft were crashed onto the Moon on mission completion. See also Luna probes; Ranger; Surveyor; Zond probes.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006