http://www.rssboard.org/rss-specification 720 http://ecuip-xtf.lib.uchicago.edu/xtf/search?expand%3Dsubject;f1-subject%3DObservatory%20(space-based);f2-subject%3DHEAO-1 Results for your query: expand=subject;f1-subject=Observatory (space-based);f2-subject=HEAO-1 Thu, 01 Jan 1970 12:00:00 GMT http://ecuip-xtf.lib.uchicago.edu/xtf/view?docId=grxr/HEAO_1/HEAO_1.dc.xml The HEAO project involved the launching of three unmanned scientific observatories into low Earth orbit between 1977 and 1979 to study some of the most intriguing mysteries of the Universe: pulsars, black holes, neutron stars, and supernovae. This artist's conception depicts the High Energy Astronomy Observatory (HEAO)-1 in orbit. HEAO-1 was launched on August 12, 1977, to survey the sky for X-ray and gamma-ray sources, as well as to pinpoint their positions. http://ecuip-xtf.lib.uchicago.edu/xtf/view?docId=grxr/HEAO_1/HEAO_1.dc.xml Thu, 01 Jan 1970 12:00:00 GMT