Astronomy:Lunar Orbiter 5

Short description: United States lunar space probe

Lunar Orbiter 5

Image of the Earth taken by Lunar Orbiter 5, enhanced by LOIRP
Mission type	Lunar orbiter
Operator	NASA
COSPAR ID	1967-075A
SATCAT no.	2907
Mission duration	183 days
Spacecraft properties
Manufacturer	Langley Research Center
Launch mass	385.6 kilograms (850 lb)
Start of mission
Launch date	August 1, 1967, 22:32:00 (1967-08-01UTC22:32Z) UTC
Rocket	Atlas SLV-3 Agena-D
Launch site	Cape Canaveral Air Force Station LC-13
End of mission
Disposal	Deorbited
Decay date	January 31, 1968 (1968-02-01)
Orbital parameters
Reference system	Selenocentric
Semi-major axis	4,846.8 kilometers (3,011.7 mi)
Eccentricity	0.26
Periselene altitude	194.5 kilometers (120.9 mi)
Aposelene altitude	6,023 kilometers (3,743 mi)
Inclination	85 degrees
Period	510.08 minutes
Lunar orbiter
Orbital insertion	August 5, 1967
Impact site	[ ⚑ ] 02.79°S 83.01°W / -02.79; -83.01
Orbits	1,380
Lunar Orbiter program

Lunar Orbiter 5, the last of the "Lunar Orbiter series", was designed to take additional Apollo and Surveyor landing site photography and to take broad survey images of unphotographed parts of the Moon's far side. It was also equipped to collect selenodetic, radiation intensity, and micrometeoroid impact data and was used to evaluate the Manned Space Flight Network tracking stations and Apollo Orbit Determination Program.

Mission summary

The spacecraft was placed in a cislunar trajectory and on August 5, 1967 was injected into an elliptical near polar lunar orbit 194.5 by 6,023 kilometres (120.9 mi × 3,742.5 mi) with an inclination of 85 degrees and a period of 8 hours 30 minutes. On August 7 the perilune was lowered to 100 kilometers (62 mi), and on August 9 the orbit was lowered to a 99-by-1,499-kilometer (62 mi × 931 mi), 3 hour 11 minute period.

The spacecraft acquired photographic data from August 6 to 18, 1967, and readout occurred until August 27, 1967. A total of 633 high resolution and 211 medium resolution frames at resolution down to 2 meters (6 ft 7 in) were acquired, bringing the cumulative photographic coverage by the five Lunar Orbiter craft to 99% of the Moon's surface. Accurate data were acquired from all other experiments throughout the mission. The spacecraft was tracked until it struck the lunar surface on command at 2.79 degrees S latitude, 83 degrees W longitude (selenographic coordinates) on January 31, 1968.

Features on the near side of the Moon that were photographic targets included Petavius, Hyginus, Messier, Tycho, Copernicus, Gassendi, Vitello, Mons Gruithuisen Gamma, Prinz, Aristarchus, Vallis Schroteri, Marius Hills, Montes Apenninus, Rimae Plato, Sinus Aestuum, Hipparchus, Rimae Sulpicius Gallus, Rimae Calippus, Censorinus, Dionysius, and the future landing site of Apollo 11.

Spacecraft orbit and photographic coverage on the near side (left) and far side (right)

Instruments

Lunar Photographic Studies :	Evaluation of Apollo and Surveyor landing sites
Meteoroid Detectors :	Detection of micrometeoroids in the lunar environment
Caesium Iodide Dosimeters :	Radiation environment en route to and near the Moon
Selenodesy :	Gravitational field and physical properties of the Moon

See also

• Lunar Orbiter Image Recovery Project
• Exploration of the Moon
• Lunar Orbiter 1
• Lunar Orbiter 2
• Lunar Orbiter 3
• Lunar Orbiter 4
• List of artificial objects on the Moon