Lunar Orbiter 3
# Lunar Orbiter 3

The Lunar Orbiter 3 was a spacecraft launched by NASA in 1967 as part of the Lunar Orbiter Program. It was designed primarily to photograph areas of the lunar surface for confirmation of safe landing sites for the Surveyor and Apollo missions. It was also equipped to collect selenodetic, radiation intensity, and micrometeoroid impact data.

## Mission summary

The spacecraft was placed in a cislunar trajectory and injected into an elliptical near-equatorial lunar orbit on February 8 at 21:54 UT. The orbit was 210.2 by 1,801.9 kilometres (130.6 mi × 1,119.6 mi) with an inclination of 20.9 degrees and a period of 3 hours 25 minutes. After four days (25 orbits) of tracking the orbit was changed to 55 by 1,847 kilometres (34 mi × 1,148 mi). The spacecraft acquired photographic data from February 15 to 23, 1967, and readout occurred through March 2, 1967. The film advance mechanism showed erratic behavior during this period resulting in a decision to begin readout of the frames earlier than planned. The frames were read out successfully until March 4 when the film advance motor burned out, leaving about 25% of the frames on the takeup reel, unable to be read.

A total of 149 medium resolution and 477 high resolution frames were returned. The frames were of excellent quality with resolution down to 1 metre (3 ft 3 in). Included was a frame of the Surveyor 1 landing site, permitting identification of the location of the spacecraft on the surface. The future landing site of Apollo 14 including Cone crater, was photographed by the orbiter. Accurate data were acquired from all other experiments throughout the mission. The spacecraft was used for tracking purposes until it struck the lunar surface on command at 14.3 degrees N latitude, 97.7 degrees W longitude (selenographic coordinates) on October 9, 1967.

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 |
