Development of observational and instrumental techniques in hard X-ray and medium energy gamma-ray astronomy

The technical activities, scientific results, related space hardware projects and personnel of the high energy astrophysics program are reported. The development of observational and instrumental techniques in hard X-ray (0.001 to 100 keV) and medium energy gamma-ray (0.1 to 10 MeV) astronomy are examined. Many of these techniques were developed explicitly for use on high altitude balloons where most of the scientific results were obtained. The extensive observational activity using balloons are tabulated. Virtually every research activity will eventually result in a major space hardware development effort.