Surveyor

Surveyor

Any of a series of seven unmanned U.S. space probes sent to make soft landings on the Moon in 1966–68. Surveyor 2 crashed on the Moon, and radio contact with Surveyor 4 was lost minutes before landing, but the rest sent back thousands of photographs; some were equipped to sample and test lunar soil. Surveyor 6 made the first liftoff from an extraterrestrial body; Surveyor 7 landed in the lunar highlands and returned data showing that the landscape and soil there differ from those of lower areas. See also Luna; Pioneer; Ranger.

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surveyor

One whose occupation is surveying, or who is otherwise skilled in the art.

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Surveyor 

the designation of a series of American spacecraft used in lunar exploration. The Surveyor program included studies to determine the mechanical characteristics, chemical composition, and electromagnetic properties of lunar soil and the thermal conditions on the surface of the moon. Television pictures of the lunar surface were obtained in order to study the topography and structure of the soil, laser emission transmitted from the earth was recorded, and astronomical investigations were conducted, including the photographing of stars, the sun, and the planets. “Surveyor” was also the name of the program for developing and launching the spacecraft in the period 1960–68. The engineering objective of the Surveyor program was the development of a system for soft landings.

The Surveyor spacecraft consisted of an engine module containing three liquid-propellant vernier rockets and a solid-pro-pellant retro-rocket, a power module with solar and chemical batteries, radio equipment, and guidance systems for flight control and orientation. The scientific apparatus included an alpha-particle scatterer and analyzer for determining the chemical composition of the lunar soil from reflected alpha particles (Surveyor 5, 6, and 7), a scoop for investigating the mechanical properties of the lunar soil (Surveyor 3, 4, and 7), instruments for detecting magnetic substances in the soil (Surveyor 4, 5, 6, and 7), and a television camera for photographing the moon in the approach area (Surveyor 1 and 2). A panoramic television camera for taking photographs after the landing on the moon was installed in all Surveyor spacecraft; a total of 86,500 photographs of the lunar surface, the sun, and the planets was taken.

The maximum diameter of all Surveyor spacecraft (measured across the extended supports of the landing chassis) was 4.27 m; the height (with chassis folded) was approximately 3 m; the weight at launch was 995–1,038 kg; and the weight after landing was 276–297 kg. An Atlas-Centaur launch vehicle was used for the launching. A total of seven spacecraft were launched in the period 1966–68, of which Surveyor 1, 3, 5, 6, and 7 accomplished a soft landing and completed the assigned tasks.

G. A. NAZAROV