Lunar Orbiter 4
Lunar Orbiter 4 was the fourth of five lunar probes of the Lunar Orbiter program of the U.S. space agency NASA. With the Lunar Orbiter program the moon should be photographically recorded and mapped in order to find landing sites for the space probes of the Surveyor program and for the manned lunar landing.
The three previous Lunar Orbiter missions were completed successfully and had provided enough pictures for the preparation of the Apollo program. For this reason, a different orbit with a larger orbital altitude ( 2706-6111 km) and higher orbital inclination ( 85.5 ° ) was selected for the fourth mission.
The photographs of the lunar surface began on 11 May 1967, and were set on May 26, after first problems with the lens cap and later with the transport mechanism of the camera had occurred. By June 1, 127 medium-resolution images and 419 high resolution images were returned to Earth. To the front of the moon was recorded at 99 % image 58-134 meters resolution.
Then the orbit was lowered to close out the irregularities of the track on mascons can. These findings were utilized for the last mission Lunar Orbiter 5. Lunar Orbiter 4 crashed on October 6, 1967 the lunar surface.