This is a segment of fused quartz that was cut off during fabrication of the X-ray mirror for the Einstein Observatory satellite. The first cosmic sources of X-ray were discovered by Richard Giacconi and his group at American Science and Engineering. They went on to develop and operate Uhuru, the first orbiting satellite dedicated to the study of X-ray sources in the Universe. The group then moved to the Smithsonian Astrophysical Observatory where they perfected imaging X-ray telescopes. Under Giacconi's leadership they developed and operated the imaging telescope on the orbiting Einstein Observatory which flew in 1978. This mirror segment was donated to NASM by AS&E in 2003 and is now stored at the Garber facility.
Gift of American Science & Engineering Incorporated.