Mission Summary
Lunar Orbiter 4 carried out the first sweeping photographic survey of the Moon’s near side, transforming a program built to scout Apollo landing sites into a tool of broad lunar science. Launched May 4, 1967, the fourth of five spacecraft in the series entered a high near-polar orbit after its predecessors had already certified the equatorial landing zones, freeing it to photograph the entire visible hemisphere.
From that vantage it imaged roughly 99 percent of the near side and a substantial portion of the far side, producing a medium-resolution atlas that guided selenologists for years. A malfunctioning camera thermal door intermittently fogged its frames, yet the spacecraft still returned striking views of the south polar region and the great Orientale basin. After controllers lost reliable command of the orbiter, its orbit decayed and it struck the Moon in October 1967.
Sources and notes can be found on the Sources page.
