The Vela satellite program for detection of high-altitude nuclear detonations

The Vela satellite high-altitude test detection system contains X-ray, gamma-ray, and neutron detectors which sense the radiations generated by a detonation in space. The satellites also contain background radiation monitors which are useful in assessing the effect of natural background radiations on the operation of the detection system. This paper contains a review of some of the problems involved in the design of the system, and a description of the instruments. Three pairs of spacecraft are currently in orbit and the detection systems are operating essentially as expected. A survey of the characteristics of the far magnetosphere and its environs, as determined from the background radiation monitors, will also be presented.