Goals: As the first in the series dedicated to scientific investigation of the Moon, Lunar Orbiter 4 was to conduct a broad, systematic, photographic survey to increase understanding of lunar surface features and to serve as a basis for selecting sites for more-detailed study by subsequent orbital and landing missions.

Accomplishments: Lunar Orbiter 4 was the first spacecraft to fly a polar orbit around the Moon. As the Moon rotated beneath its flight path, It imaged almost all of the Moon's near side and three-quarters of the far side, and took the first photo of the lunar south pole. It also gathered gravitational data in preparation for Lunar Orbiter 5.