Chandra (def.): Launched on July 23, 1999, it is the largest and most sophisticated X-ray observatory to date.
NASA's Chandra X-ray Observatory is a telescope specially designed to detect X-ray emission from very hot regions of the Universe such as exploded stars, clusters of galaxies, and matter around black holes. Because X-rays are absorbed by Earth's atmosphere, Chandra must orbit above it, up to an altitude of 139,000 km (86,500 mi) in space. As its mission progresses, Chandra will continue to discover startling new science about our high-energy Universe. More >