Mirror assembly complete for x-ray astrophysics facility

17 Jun 2002

The world's most powerful X-ray observatory came a major step closer to completion recently with the assembly of its high resolution mirrors. The last of four pairs of unique mirrors which form the heart of NASA's Advanced X-ray Astrophysics Facility (AXAF) were aligned and cemented into place at Eastman Kodak's Federal Systems Division in Rochester, New York, last month.

Unlike the concave, nearly flat mirrors used in optical telescopes, the AXAF mirrors are shallow, almost cylindrical cones. The four pairs of mirrors are nested inside each other. X-rays enter the telescope, graze off the mirrors -- much like a stone skipping across the surface of a pond -- and are focused onto a plane 30 feet behind the front of the mirrors.

The largest of the mirrors is 47.2 inches, which makes this mirror set the largest ever made. The size and accuracy of the mirrors will make AXAF 100 time more sensitive than previous X-ray telescopes, producing images 10 times sharper. The observatory, scheduled for a Space Shuttle launch in 1998, is expected to obtain never-before-seen images of highly energized X-ray sources -- such as neutron stars, black holes, debris from exploding stars, quasars, centers of galaxies and galaxy clusters.