Astro E

Astro E is an X-ray astronomy satellite built as a joint effort of NASA and the Japanese space agency ISAS. Observing the X-ray spectrum of the distant universe, Astro-E was to open a new window into the workings of black holes, neutron stars, active galaxies, and other very energetic objects. Astro E featured four instruments, among them NASA's XRS spectrometer inherited from the cancelled AXAF-S mission.