Definitions

celestial photography

Surveyor 1

Surveyor 1 was the first lunar lander in the American Surveyor program that explored the Moon. The program was managed by the NASA Jet Propulsion Laboratory, utilizing spacecraft designed and built by Hughes Aircraft.

A total 11,237 images were transmitted to Earth.

The successful soft landing in the Ocean of Storms was the first ever by the U.S. on an extraterrestrial body, and came just four months after the landing of the Soviet Luna 9 mission.

Mission description

The Surveyor spacecraft was designed to attain the engineering objectives of the Surveyor program, which included the first lunar soft landing by an American spacecraft. No instrumentation was carried specifically for scientific experiments, but considerable scientific information was obtained. The spacecraft carried two television cameras - one for approach, which was not used, and one for operations on the lunar surface. Over 100 engineering sensors were on board. The television system transmitted pictures of the spacecraft footpad and surrounding lunar terrain and surface materials. The spacecraft also acquired data on the radar reflectivity of the lunar surface, bearing strength of the lunar surface, and spacecraft temperatures for use in the analysis of the lunar surface temperatures.

The spacecraft was launched May 30, 1966, directly into a lunar impact trajectory. Engines were turned off at a height of 3.4 m above the lunar surface. The spacecraft fell freely from this height, landing on the lunar surface on June 2, 1966, in Oceanus Procellarum - 2.45 deg s latitude, 43.22 deg w longitude (selenographic coordinates). The spacecraft transmitted data from shortly after touchdown until July 14, 1966, with an interval of no operation during lunar night (June 14 to July 7, 1966). Engineering interrogations continued until January 7, 1967.

Science instruments

Television

The TV camera consisted of a vidicon tube, 25 and 100 mm focal length lenses, shutter, filters, and iris mounted along an axis inclined approximately 16 deg to the central axis of the spacecraft. The camera was mounted under a mirror that could be moved in azimuth and elevation. Camera operation was totally dependent upon the receipt of the proper command structure from earth. Frame by frame coverage of the lunar surface was obtained over 360 deg in azimuth and from +40 deg above the plane normal to the camera Z axis to -65 deg below this plane. Both 600 line and 200 line modes of operation were used. The 200 line mode transmitted over an omnidirectional antenna for the first 14 photos and scanned one frame every 61.8 seconds. The remaining transmissions were of 600 line pictures over a directional antenna, and each frame was scanned every 3.6 seconds. Each 200 line picture required 20 seconds for a complete video transmission and utilized a bandwidth of 1.2 kHz. Each 600 line picture required nominally 1 second to be read from the vidicon and required a 220 kHz bandwidth for transmission. The data transmissions were converted to a standard television signal for closed circuit and public broadcast television. The television images were displayed on earth on a slow scan monitor coated with a long persistency phosphor. The persistency was selected to optimally match the nominal maximum frame rate. One frame of TV identification was received for each incoming TV frame and was displayed in real time at a rate compatible with the incoming image. These data were recorded on a video magnetic tape recorder. Over 10,000 pictures were taken by the Surveyor 1 camera before lunar sunset on June 14, 1966. Included were wide and narrow angle panoramas, focus ranging surveys, photometric surveys, special area surveys, and celestial photography. The spacecraft responded to commands to activate the camera on July 7 and, by July 14, 1966, returned nearly another 1000 frames.

Strain gauge

Strain gauges were mounted on each leg shock absorber to record the peak axial forces at landing impact of the spacecraft. They were designed to accept a force of approximately 800 kgf (7.8 kN).

See also

  • Luna 9 - First successful lander (Soviet Union)

External links

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