Several Ranger spacecraft had a gamma-ray spectrometer that consisted of a detector, a 32 channel pulse height analyzer, and a high-voltage power supply was designated to measure the gamma radiation coming from the surface of the Moon. This is part of a mock-up of Ranger VIII. Ranger VIII was a spacecraft that was designed as a hard lander on the Moon. During its final minutes up of flight before impact, Ranger VIII transmitted high-resolution photography of the lunar surface. The spacecraft carried six television video cameras, two full-scan cameras, and four partial scan cameras. Ranger VIII was launched on February 17, 1965, and reached the Moon on February 20, 1965. During its final 23 minutes of flight, Ranger VIII transmitted over 7,000 good quality photographs.
NASA's Jet Propulsion Laboratory transferred this object to the Smithsonian Institution in 1973.
Gift of William A. Saley
A gamma-ray spectrometer that consisted of a detector, a 32 channel pulse height analyzer, and a high-voltage power supply was designated to measure the gamma radiation coming from the surface of the moon. The detector contained a beveled 7.62-cm diam cesium iodide crystal surrounded in a phoswich arrangement by a plastic scintillator of .317-cm thickness. This was coupled to a 7.62-cm diam photomultiplier tube. Pulses were passed into the analyzer, which was provided with storage for 2 to the 16th pulses in each channel. Reject circuitry was designed to block the analyzer when charged particles traversed the phoswich. The experiment was turned on 4 hr after liftoff, with data storage and telemetry beginning at once. A loss of power in the spacecraft caused experiment telemetry to cease after 4 hr of data and been received.