The 1966 Lunar Orbiter 1

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mission, part of

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeedin ...

's Lunar Orbiter program, was the first American spacecraft to orbit the Moon. It was designed primarily to photograph smooth areas of the

lunar Lunar most commonly means "of or relating to the Moon". Lunar may also refer to: Arts and entertainment * ''Lunar'' (series), a series of video games * "Lunar" (song), by David Guetta * "Lunar", a song by Priestess from the 2009 album ''Prior t ...

surface for selection and verification of safe landing sites for the

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and

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missions. It was also equipped to collect selenodetic,

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intensity, and

micrometeoroid A micrometeoroid is a tiny meteoroid: a small particle of rock in space, usually weighing less than a gram. A micrometeorite is such a particle that survives passage through Earth's atmosphere and reaches Earth's surface. The term "micrometeor ...

impact data.

Mission Summary

Mission controllers injected the spacecraft into a parking orbit around

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on August 10, 1966, at 19:31 UTC. The

trans-lunar injection A trans-lunar injection (TLI) is a propulsive maneuver used to set a spacecraft on a trajectory that will cause it to arrive at the Moon. History The first space probe to attempt TLI was the Soviet Union's Luna 1 on January 2, 1959 which w ...

burn occurred at 20:04 UTC. The spacecraft experienced a temporary failure of the

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star tracker (probably due to stray sunlight) and overheating during its cruise to the

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. The star tracker problem was resolved by navigating using the Moon as a reference, and the overheating was abated by orienting the spacecraft 36 degrees off-Sun to lower the temperature. Lunar Orbiter 1 was injected into an elliptical near-equatorial lunar orbit 92.1 hours after launch. The initial orbit was and had a period of 3 hours 37 minutes and an inclination of 12.2 degrees. On August 21, perilune was dropped to and on August 25 to . The spacecraft acquired photographic data from August 18 to 29, 1966, and readout occurred through September 14, 1966. Lunar Orbiter 1 coverage

A total of 42 high-resolution and 187 medium-resolution frames were taken and transmitted to Earth covering more than 5 million square kilometers of the Moon's surface, accomplishing about 75% of the intended mission, although a number of the early high-resolution photos showed severe smearing. It also took the first two pictures of Earth from the Moon. Accurate data were acquired from all other experiments throughout the mission. While not disclosed until after the end of the

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, the imaging system on the Lunar Orbiter spacecraft were the same

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cameras developed by the National Reconnaissance Office (NRO) for the

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reconnaissance satellites. NASA extended the camera innovation further by developing the film onboard the spacecraft and then scanning the photos for transmission via a video signal. Orbit tracking showed a slight "pear-shape" of the Moon based on the gravity field, and no micrometeorite impacts were detected. The spacecraft was tracked until it impacted the lunar surface on command at 7 degrees north latitude, 161 degrees east longitude ( selenographic coordinates) on the Moon's far side on October 29, 1966, on its 577th orbit. The early end of the nominal one-year mission resulted from a shortage of remaining attitude control gas and other deteriorating conditions and was planned to avoid transmission interference with Lunar Orbiter 2. Image:First View of Earth from Moon.jpg, The first image of Earth from the distance of the Moon, August 23, 1966. This probe took a second such image on August 25. Image:First View of Earth from Moon - reprocessed.png, Part of the photo to the left as reprocessed by LOIRP in 2008. Image:First View of Earth from Moon - reprocessed wide.jpg, Full reprocessed image from 2008.

References

{{NASA space program 1 Spacecraft launched in 1966 Spacecraft that orbited the Moon Spacecraft that impacted the Moon 1966 on the Moon

Mission Summary

See also

References