THE LUNAR ORBITER 3 MISSION

Mission Description

Launch:  5 February 1967
Imaged Moon:  15-23 February 1967
Apollo landing site survey mission

The primary objective of Lunar Orbiter 3 was to continue the Orbiter 1 and Orbiter 2 task of photographing promising areas of the lunar surface to determine their adequacy as Apollo and/or Surveyor landing sites. Mission 3 differed from the previous two missions in that it was a site confirmation mission rather than a site selection mission. To provide access to both mission 1 and 2 primary sites with acceptable lighting conditions, the orbit inclination of this mission was increased to 21°. Mission photography was conducted as planned except for minor shifts in some photo site locations, the addition of a fourth pass over the Surveyor 1 landing site, and the cancellation of the last secondary site. During 54 successive orbits, a total of 211 exposures were taken. Unfortunately, only about 75% of these were transmitted before a failure in the film-advance motor terminated the readout operation.

Selection of the Target Sites

Primary photo site selection was based on screening of the Lunar Orbiter 1 and 2 photographs. Twelve primary sites (including the landing area of Surveyor 1) and 32 secondary sites were selected. The secondary sites included different terrain types from Apollo support sites, which were all maria. They provided information of value in selection of nonmare Surveyor landing sites.