Project Ranger

NASA’s Ranger program, operated by the Jet Propulsion Laboratory at the California Institute of Technology, was a series of unmanned missions to the Moon during the mid-1960s. The objective of the program was to obtain high-resolution photographs of the lunar surface in advance of Surveyor and Apollo lunar landing missions.

Ranger flight profile on approach to the Moon. Rangers were launched aboard Atlas-Agena rockets from Cape Canaveral, Florida. The probe was about 12 feet in height with two, five-foot solar panels that provided electrical power to the spacecraft. Image source: Gatland, Kenneth W. Robot Explorers. London, Blandford Press, 1972. 

Built to Crash

Ranger spacecraft were sent on a collision course to the Moon. They were designed to transmit close-up photographs of the lunar surface a few minutes before they crashed. The first six Ranger flights failed to reach the Moon. The final three flights successfully impacted the lunar surface, transmitting thousands of detailed images back to Earth.

Camera arrangement inside a Ranger spacecraft. Image source: Hall, R. Cargill. Project Ranger: A Chronology. Jet Propulsion Laboratory, 1971. 

Cameras

Each Ranger spacecraft contained six vidicon television cameras manufactured by RCA. The cameras had varying exposure times and fields of view. Three of the six cameras used 25-mm lenses; the other three had 76-mm lenses.