Ranger

Ranger

Any of a series of unmanned probes launched from 1961 to 1965 by NASA. The project was NASA's earliest attempt to explore the Moon's surface. Ranger 4 (1962) became the first U.S. spacecraft to hit the Moon, crash-landing on its surface as planned. The last three probes in the series (1964–65) sent more than 17,000 high-resolution photographs of the Moon before crashing. See also Luna; Pioneer; Surveyor.

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wale, waler, whaler

A horizontal timber or beam used to brace or support an upright member, as sheeting, formwork for concrete, etc. (See illustration p. 1052.)

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Ranger 

the name of a series of American spacecraft for lunar exploration (with the exception of Rangers 1 and 2, which were put into geocentric orbits and were designed to test onboard systems) and of the program for developing and launching these spacecraft (1959–65). The spacecraft were launched by Atlas-Agena Blaunch vehicles, with the exception of Ranger 8, which was launched by an Atlas-Agena D.

Rangers 3, 4, and 5 were similar in design and had six television cameras. The flight objectives were to obtain television pictures of the lunar surface, to conduct radar scanning of the moon and study the characteristics of lunar rocks using a gamma-ray spectrometer, and to accomplish a semisoft landing with an instrument package containing a seismometer. No soft landing on the moon was envisioned. After the unsuccessful flights of Rangers 3, 4, and 5, succeeding craft were modified, and two sets of three television cameras each were installed in place of the lunar capsule. The television equipment on Ranger 6 malfunctioned, and no pictures were made. During the lunar approaches of Rangers 7, 8, and 9, more than 17,000 photographs of the lunar surface were taken in the regions of Mare Cognitum, Mare Tranquillitatis, and the crater Alphonsus.

The maximum diameter of all Ranger spacecraft was 1.52 m, the height was 2.52 m with antenna and solar panels stowed and 3.12 m with the equipment extended, and the maximum cross-sectional dimension was 5.18 m; the weight was between 306 and 367 kg. The power supply system included solar cells and silver-zinc batteries, and the vernier engine installation operated on monopropellant fuel.

G. A. NAZAROV