Surveyor model on Earth
Surveyor 7 was the seventh and last lunar lander of the
American unmanned
Surveyor program sent to explore the surface of the
Moon. A total of 21,091 pictures were transmitted to Earth.
Surveyor 7 was the fifth and final spacecraft of the Surveyor series to achieve a lunar
soft landing.
The objectives for this mission were to perform a lunar soft landing
(in an area well removed from the maria to provide a type of terrain
photography and lunar sample significantly different from those of other
Surveyor missions); obtain postlanding TV pictures; determine the
relative abundances of chemical elements; manipulate the lunar material;
obtain touchdown dynamics data; and obtain thermal and radar
reflectivity data. This spacecraft was similar in design to the previous
Surveyors, but it carried more scientific equipment including a
television camera with polarizing filters, a surface sampler, bar
magnets on two footpads, two horseshoe magnets on the surface scoop, and
auxiliary mirrors. Of the auxiliary mirrors, three were used to
observe areas below the spacecraft, one to provide stereoscopic views
of the surface sampler area, and seven to show lunar material deposited
on the spacecraft. The spacecraft landed on the
lunar surface on January 10, 1968, on the outer rim of the
crater Tycho.
Operations of the spacecraft began shortly after the soft landing and
were terminated on January 26, 1968, 80 hours after sunset. On January
20, while the craft was still in daylight, the TV camera clearly saw
two laser beams aimed at it from the night side of the crescent Earth,
one from Kitt Peak National Observatory, Tucson, Arizona, and the other
at Table Mountain at Wrightwood, California.
Operations on the second lunar day occurred from February 12 to 21,
1968. The mission objectives were fully satisfied by the spacecraft
operations. Battery damage was suffered during the first lunar night and
transmission contact was subsequently sporadic. Contact with Surveyor 7
was lost on February 21, 1968.
It was planned to be visited by the cancelled Apollo 20 mission,
however Skylab and subsequent budget cuts stopped this from happening.
Photomosaic of a panorama taken by Surveyor 7 of its landing site
Surveyor 7 was the first probe to detect the faint glow on the lunar
horizon after dark that is now thought to be light reflected from
electrostatically levitated
moon dust.