The Vanguard Cosmic Ray Instrument

his chapter addresses the development of the cosmic ray instrument for the Van­guard satellite program at the University of Iowa. It covers the period from the experiment’s first proposal in 1954 until the launch of Sputnik 1 in October 1957. The launch of the Soviet satellite resulted in a major shift in the Iowa program.

At that point, the decision was quickly made for the army to proceed with a parallel satellite program using their Jupiter C-based launch vehicle. A small portion of the Vanguard instrument that is described in this chapter was extracted to form the very simple primary scientific instrument launched in January 1958 on Explorer I. The full Vanguard package that is described here, with some minor modifications to adapt it to the different launch vehicle and the expanded network of ground receiving stations, was successfully launched shortly thereafter as Explorer III.

Although the instrument was certainly simple by today’s standards, it did mark an important step in the evolution of remotely operated robotic devices in a new en­vironment. Some of the details of this instrument’s architecture and circuit design have been previously described.1 However, an account of the elaborate process of instrument development, testing, and launch, including the many special problems that were encountered, has not been previously available.

Those not interested in the many technical details of developing an early scientific instrument for use in space may want to read the opening sections of this chapter and then move on to the account of the first Sputnik launch in the next chapter.

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OPENING SPACE RESEARCH