In 1970, the United States sent its first X-ray telescope into space. In honor of its Kenyan launch site, the telescope was named Uhuru, Swahili for "freedom." Uhuru spent three years scanning the sky for X-ray sources that could never have been detected from the ground.
Twenty-nine years later, NASA launched the most sophisticated X-ray observatory it had ever built: the Chandra X-ray Observatory, named after the Nobel prize-winning physicist Subrahmanyan Chandrasekhar.
Chandra is positioned 200 times higher than the Hubble Space Telescope, in an elliptical, or oval-shaped, orbit. It has been able to detect X-ray sources 20 times fainter than anything previously picked up by an x-ray telescope and can be used to study objects that emit X-rays, such as black holes, supernovae and dark matter.
X-rays, unlike visible light rays, are rarely observed and difficult to catch. Chandra, the third telescope in NASA’s Great Observatories program, captures its X-rays with barrel-shaped mirrors unlike anything on a telescope that studies visible light.

Enlarge
picture
| Year launched: | 1999 |
| Telescope type: | Reflector |
| Light collector: | 8 iridium-coated glass mirrors |
| Mirror diameter: | Each
32.8 inches (83.3 cm) |
| Light observed: | X-ray |