This is a rebuilt engineering prototype of the first Small Astronomy Satellite, or SAS - 1. SAS-1 was devoted exclusively to the study of non-solar x-rays in space. It was launched by an international team from a platform off the coast of Kenya on December 12, 1970. It was named Uhuru, meaning freedom in Swahili, to mark the fact that the date represented the 7th anniversary of Kenyan independence. Uhuru scanned the x-ray sky using two collimated x-ray telescopes pointing in opposite directions. In its three years of operation it mapped more than 200 x-ray sources and provided early evidence for the existence of black holes as well as a binary x-ray source. The components were originally operational except for the solar panels that are non-operational imitations. Transferred from NASA in 1976, the artifact was displayed in the "Satellites" Gallery from 1976 to 1982 and then in the "Stars" gallery from 1983 through 1997. It was restored in 1998 (one of the star sensors was dented while it was on display).