Herbert Gursky coauthored the 1962 rocket experiment that detected X-rays from beyond the Solar system. Large-area counters carried above the absorbing atmosphere recorded a strong celestial source as well as a more diffuse background.
The payload's changing direction allowed count rate to be compared with sky direction, separating a localized source from broadly distributed counts. The experiment opened X-ray astronomy to objects whose energetic emission could not be measured by ordinary ground-based optical observations.[ref]
Evidence for x Rays From Sources Outside the Solar System by Riccardo Giacconi and others. Author list and pp. 439–443: rocket counters, directional count rates and extrasolar radiation
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