Camera, Television, Surveyor

The Surveyor probes of the 1960s were the first U.S. spacecraft to land safely on the Moon and each was equipped with a television camera with parts identical to the test article shown here. This camera consisted of a vidicon tube, 25- and 100-mm focal length lenses, shutters, and color filters. This unit, missing the motor drive, mirror, and hood was used for bench tests of the optics.

This object was transferred from NASA, Marshall Space Flight Center

The TV camera for all Surveyor spacecraft consisted of a vidicon tube, 25- and 100-mm focal length lenses, shutters, color filters, and iris mounted along an axis inclined approximately 16 degrees 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 receipt of the proper command structure from Earth. Frame-by-frame coverage of the lunar surface was obtained over 360 degrees in azimuth and from +40 degrees above the plane normal to the camera z axis to -65 degrees below this plane. Both 600-line and 200-line modes of operation were used. The 200-line mode transmitted over an omnidirectional antenna and scanned one frame each 61.8 seconds. A complete video transmission of each 200-line picture required 20 seconds and utilized a bandwidth of 1.2 kHz. Most transmissions consisted of the 600-line pictures, which were telemetered by a directional antenna. These frames were scanned each 3.6 seconds. Each 600-line picture required nominally 1 second to be read from the vidicon and utilized a 220-kHz bandwidth for transmission. The television images were displayed on a slow scan monitor coated with a long persistency phosphor. The persistency was selected to 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 that of the incoming image. These data were then recorded on a video magnetic tape recorder and on 70-mm film. The camera performance throughout the successful Surveyor missions was excellent in terms of both the quantity and quality of pictures.