Chandra X-ray Observatory(Advanced X-ray Astrophysics Facility (AXAF)): Launched by NASA on July 23, 1999. Specialist in X-Ray Astronomy. Still in orbit as on date -2015.
Chandra is one of the Great Observatories, along with the Hubble Space Telescope, Compton Gamma Ray Observatory (1991–2000), and the Spitzer Space Telescope(Infrared Space Observatory- NASA). The telescope is named after astrophysicist Subrahmanyan Chandrasekhar.
How it is different from traditional telescopes?
Since the Earth’s atmosphere absorbs the vast majority of X-rays, they are not detectable from Earth-based telescopes; therefore space-based telescopes are required to make these observations. Chandra is an Earth satellite in a 64-hour orbit.