This is the flight spare main amplifier for the antenna apparatus carried on the Orbiting Geophysical Observatory V (OGO-V) designed to measure the energy characteristics in the radiation belts surrounding the Earth. This solid state device, which was located in the main bus of the satellite, took signals from the sensor antenna (Catalogue #19860560000). This amplifier was manufactured by the Space and Technology Group of TRW; the firm donated it to the Museum in February 1985.
OGO-V was the fifth in a series of standardized spacecraft capable of performing many related experiments that were launched during the middle 1960s. The sensor formed part of an experiment that measured the electrostatic and electromagnetic properties of the plasma ranging from the upper ionosphere to the solar wind. The flight model of the plasma wave detector was placed in orbit from Cape Kennedy on March 4, 1968. Data from this instrument provided the first evidence for the shock wave observed in the solar wind as it encounters the Earth's magnetic field, the so-called bow shock.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.