[Lunar Orbiter III]

NASA, NASA Contractor Report, NASA CR-1069, Lunar Orbiter III, Photographic Mission Summary, Seattle, WA: The Boeing Company, May 1968, p. 101

NASA, NASA Space Science Data Coordinated (NSSDC) Image Catalog, Mission Index, The Moon - Lunar Orbiter 3, Greenbelt, MD: NASA Goddard Space Flight Center, September 2015

Lunar Orbiter III was NASA’s final Lunar Orbiter mission to study potential landing sites for the Apollo missions. Known as the site-confirmation mission, the primary objective of Lunar Orbiter III was to photograph the 12 potential Apollo landing sites previously identified by Lunar Orbiters I and II in higher resolution and from vertical, oblique, and forward wide-angles. Though only 75% of the 211 photographs were successfully transmitted back to earth, the surviving photograph data allowed NASA scientists to narrow the landing sites down to eight possibilities by early April 1967, including the sites where Apollo 11 and Apollo 13 would disembark. Aside from potential landing sites, the mission also targeted secondary sites of scientific interest on the farside of the moon and at higher altitudes on the nearside. This image of the farside of the moon, taken at an altitude of 58.98 km high, shows the lunar equator and the south pole on the horizon, as well as the prominent Tsiolkovsky crater.