Spacecraft above the Moon.

An artist's concept of NASA's Lunar Orbiter at the Moon.

What was Lunar Orbiter 2?

NASA's Lunar Orbiter 2's primary mission was to photograph smooth areas of the lunar surface to help select safe landing sites for the Apollo missions. The spacecraft took photos covering nearly 1.6 million square miles (4 million square kilometers) of the Moon's surface.

Nation United States of America (USA)
Objective(s) Lunar Orbit
Spacecraft LO-B (Spacecraft 5)
Spacecraft Mass 850 pounds (385.6 kilograms)
Mission Design and Management NASA / LaRC
Launch Vehicle Atlas Agena D (Atlas Agena D no. 18 / Atlas D no. 5802 / Agena D no. AD122/6631)
Launch Date and Time Nov. 6, 1966 / 23:21:00 UT
Launch Site Cape Canaveral, Fla. / Launch Complex 13
Scientific Instruments 1. Imaging System
2. Micrometeoroid Detectors
3. Radiation Dosimeters

Key Dates

Nov. 6, 1966: Launch

Nov. 10, 1966: Spacecraft arrived in lunar orbit

Nov. 18, 1966: Photography mission began

Oct. 11, 1967: Spacecraft deliberately crashed on the Moon

In Depth: Lunar Orbiter 2

Lunar Orbiter 2’s mission was to photograph 13 primary and 17 secondary landings sites for the Apollo program in the northern region of the Moon’s near side equatorial area.

After a course correction on the way to the Moon, on Nov. 10, 1966, the spacecraft entered a 122 × 1,150-mile (196 × 1,850-kilometer) orbit around the Moon. After 33 orbits, Lunar Orbiter 2 was moved to its photographic orbit with a perilune (closest point to the surface) of about 31 miles (49.7 kilometers).

On Nov. 18, 1966, Lunar Orbiter 2 began its photography mission, returning excellent quality medium and high-resolution photographs, including the impact point of Ranger 8. The spacecraft ended its photography mission Nov. 26, 1966, and transmission of the images was concluded Dec. 7, 1966, by which time the probe had transmitted back 211 pictures of both the near side of the Moon and large areas of the far side.

These photos covered nearly 1.6 million square miles (4 million square kilometers) of the lunar surface. The high-gain transmitter failed during this time but did not significantly affect the coverage afforded by the photos.

On Nov. 23, 1966, Lunar Orbiter 2 took perhaps the most memorable photo of any in the series, a spectacular shot looking across the Copernicus crater from an altitude of only 28 miles (45 kilometers) that vividly emphasized the three-dimensional nature of the lunar surface.

On Dec. 8, 1966, after the main photographic mission was over, Lunar Orbiter 2 fired its main engine to change its orbital plane in order to provide tracking data of the Moon’s gravitational field over a wider swath.

Finally, on Oct. 11, 1967, when attitude control gas was almost depleted, a retro-burn deliberately crashed the spacecraft onto the lunar surface at 4 degrees south latitude and 98 degrees east longitude on the far side of the Moon to prevent communications interference on future missions.

Key Source

Siddiqi, Asif A. Beyond Earth: A Chronicle of Deep Space Exploration, 1958-2016. NASA History Program Office, 2018.

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