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NSSDCA ID: 1962-012A-01

Mission Name: Ranger 4
Principal Investigator:Dr. Gerard P. Kuiper


The telescopic vidicon television camera was designed to transmit closeup pictures of the lunar surface from 4000 to 47 km above the moon. The system contained an all-electrostatic deflection and focus vidicon which combined a target with rapid erase capability. The exposure time of 20 msec on the photoconductor surface was designed to prevent blurring of the optical image and to provide a closing of the optical system during the 13-sec scan and erase operation of the vidicon electronic system. The slowly decaying image and subsequent scanning yielded one complete frame in 10 sec. To achieve the desired resolution, 200 scanning lines were employed per frame. The video bandwidth for this system was appromimately 200 cps. The optical system developed was a conventional cassegrain configuration astronimical telescope employing a primary concave parabolic mirror and a centrally located secondary convex hyperbolic mirror for reflecting the lunar image on the photoconductive image surface. The experiment failed due to spacecraft communications problems shortly after launch (from 460 sec to 25 min).

Alternate Names

  • Ranger4/Television


  • Planetary Science: Geology and Geophysics

Additional Information

Questions and comments about this experiment can be directed to: Coordinated Request and User Support Office



NameRoleOriginal AffiliationE-mail
Dr. Gerard P. KuiperPrincipal InvestigatorUniversity of Arizona
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