Lunar Orbiter (1966 - 1967)

Five Lunar Orbiter missions were launched in 1966 through 1967 with the purpose of mapping the lunar surface before the Apollo landings. All five missions were successful, and 99% of the Moon was photographed with a resolution of 60 m or better. The first three missions were dedicated to imaging 20 potential lunar landing sites, selected based on Earth-based observations. These were flown at low inclination orbits. The fourth and fifth missions were devoted to broader scientific objectives and were flown in high altitude polar orbits. Lunar Orbiter 4 photographed the entire nearside and 95% of the farside, and Lunar Orbiter 5 completed the farside coverage and acquired medium (20 m) and high (2 m) resolution images of 36 pre-selected areas. The images at the top of the page show the Lunar Orbiter spacecraft with the high and medium resolution cameras at the center, and an image of the crater Tycho taken with the Lunar Orbiter 5 medium resolution camera.

Lunar Orbiter 4 image of the Moon centered on the Mare Orientale Basin. The outermost circle of the "bull's eye" is the Cordillera Mountain scarp, almost 900 kilometers in diameter

For detailed information on the experiments and data sets held at NSSDCA, click on the mission name.

Lunar Orbiter 1

Launched 10 August 1966
Imaged Moon: 18-29 August 1966
Apollo landing site survey mission

Lunar Orbiter 2

Launched 06 November 1966
Imaged Moon: 18-25 November 1966
Apollo landing site survey mission

Lunar Orbiter 3

Launched 05 February 1967
Imaged Moon: 15-23 February 1967
Apollo landing site survey mission

Lunar Orbiter 4

Launched 04 May 1967
Imaged Moon: 11-26 May 1967
Lunar mapping mission

Lunar Orbiter 5

Launched 01 August 1967
Imaged Moon: 06-18 August 1967
Lunar mapping and hi-res survey mission

The Lunar Orbiters had an ingenious imaging system, which consisted of a dual-lens camera, a film processing unit, a readout scanner, and a film handling apparatus. Both lenses, a 610-mm narrow angle high-resolution (HR) lens and an 80-mm wide-angle medium resolution (MR) lens, placed their frame exposures on a single roll of 70 mm film. The axes of the two cameras were coincident so the area imaged in the HR frames were centered within the MR frame areas. The film was moved during exposure to compensate for the spacecraft velocity, which was estimated by an electric-optical sensor. The film was then processed, scanned, and the images transmitted back to Earth.

These images show the L.O. 5 high resolution camera view of part of Tycho crater (corresponding to the medium resolution view shown at the top of the page), and a Lunar Orbiter 2 northward oblique view of the Marius Hills in Oceanus Procellarum. The crater at the upper right of the image is Marius crater, 41 kilometers in diameter.

Detailed Information on Lunar Orbiters and Images

Images of the Moon - Lunar Orbiter and Other Spacecraft

Digital Lunar Orbiter Photographic Atlas of the Moon - Lunar and Planetary Institute

Digitized Lunar Orbiter Images - USGS/PDS

Lunar Orbiter Image Recovery Project - NASA Ames

Destination Moon: A History of the Lunar Orbiter Program - NASA History Office

Guide to Lunar Orbiter Photographs (PDF File) - USGS Astrogeology Branch

Moon home page
Lunar Exploration home page

Author/Curator:
Dr. David R. Williams, dave.williams@nasa.gov
NSSDCA, Mail Code 690.1
NASA Goddard Space Flight Center
Greenbelt, MD 20771
+1-301-286-1258