Lunar Orbiter Program

Five Lunar Orbiter missions mapped the Moon before the Apollo landings.

Occurred 57 years ago

Mission Type

Lunar Orbiters

No. of Missions

First Launch

Aug. 10, 1966

Final Mission

Aug. 18, 1967

An overhead view of Copernicus crater shows ridges and cliffs extended to a dark horizon.

This Lunar Orbiter 2 image of Copernicus crater was called the "picture of the century" in 1966. At the time, most lunar photos were taken from straight above. This image revealed the complex topography of the Moon in unprecedented detail.

NASA

The Lunar Orbiter Program

Spacecraft	Launch Date	Purpose	Results
Lunar Orbiter 1	Aug 10, 1966	Apollo Landing Site Survey	Successful
Lunar Orbiter 2	Nov 6, 1966	Apollo Landing Site Survey	Successful
Lunar Orbiter 3	Feb 5, 1967	Apollo Landing Site Survey	Successful
Lunar Orbiter 4	May 4, 1967	Lunar Mapping	Successful
Lunar Orbiter 5	Aug 1, 1967	Lunar Mapping / High-Resolution Survey	Successful

Lunar Orbiters photographed 99% of the Moon. The first three missions focused on imaging 20 potential Apollow lunar landing sites. These were flown at low inclination orbits. The final two missions were flown at high altitude polar orbits.

The orbiters carried a dual-lens camera, a film processing unit, a readout scanner, and a film-handling apparatus. Both lenses placed their exposures on a single roll of 70 mm film. The film was moved during exposure to compensate for the spacecraft velocity, which was estimated by an optical sensor. The film was then processed, scanned, and the images transmitted back to Earth.

Lunar Orbiter 4 photographed the entire nearside and 95% of the farside. Lunar Orbiter 5 completed the farside coverage and took more detailed images of 36 key areas.