The 1966 Lunar Orbiter 1 robotic spacecraft 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, succeeding t ...

Lunar Orbiter program The Lunar Orbiter program was a series of five uncrewed lunar orbiter missions launched by the United States from 1966 through 1967. Intended to help select Apollo landing sites by mapping the Moon's surface, they provided the first photographs f ...

, 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 Surveyor and

Apollo Apollo, grc, Ἀπόλλωνος, Apóllōnos, label=genitive , ; , grc-dor, Ἀπέλλων, Apéllōn, ; grc, Ἀπείλων, Apeílōn, label=Arcadocypriot Greek, ; grc-aeo, Ἄπλουν, Áploun, la, Apollō, la, Apollinis, label= ...

missions. It was also equipped to collect selenodetic,

radiation In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes: * ''electromagnetic radiation'', such as radio waves, microwaves, infrared, visi ...

intensity, and micrometeoroid impact data.

Mission Summary

Mission controllers injected the spacecraft into a

parking orbit A parking orbit is a temporary orbit used during the launch of a spacecraft. A launch vehicle boosts into the parking orbit, then coasts for a while, then fires again to enter the final desired trajectory. The alternative to a parking orbit is ''di ...

around

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

on August 10, 1966, at 19:31 UTC. The trans-lunar injection burn occurred at 20:04 UTC. The spacecraft experienced a temporary failure of the

Canopus Canopus is the brightest star in the southern constellation of Carina and the second-brightest star in the night sky. It is also designated α Carinae, which is Latinised to Alpha Carinae. With a visual apparent magnitude ...

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

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

. 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 An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any ellip ...

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

Cold War The Cold War is a term commonly used to refer to a period of geopolitical tension between the United States and the Soviet Union and their respective allies, the Western Bloc and the Eastern Bloc. The term '' cold war'' is used because the ...

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

Eastman Kodak The Eastman Kodak Company (referred to simply as Kodak ) is an American public company that produces various products related to its historic basis in analogue photography. The company is headquartered in Rochester, New York, and is incorpor ...

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

SAMOS Samos (, also ; el, Σάμος ) is a Greece, Greek island in the eastern Aegean Sea, south of Chios, north of Patmos and the Dodecanese, and off the coast of western Turkey, from which it is separated by the -wide Mycale Strait. It is also a se ...

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 The selenographic coordinate system is used to refer to locations on the surface of Earth's moon. Any position on the lunar surface can be referenced by specifying two numerical values, which are comparable to the latitude and longitude of Earth. ...

) 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 The 1966 Lunar Orbiter 2 robotic spacecraft mission, part of the Lunar Orbiter Program, was designed primarily to photograph smooth areas of the lunar surface for selection and verification of safe landing sites for the Surveyor and Apollo mi ...

. 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 The Lunar Orbiter Image Recovery Project (LOIRP) is a project to digitize the original analog data tapes from the five Lunar Orbiter spacecraft that were sent to the Moon in 1966 and 1967; it is funded by NASA, SkyCorp, SpaceRef Interactive, a ...

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