Chandra Has Been X-Raying the Universe for 15 YearsMika McKinnon (email@example.com)7/23/14 12:40pmFiled to: chandranasasupernovabirthdayEarth And Space138EditPromoteShare to KinjaToggle Conversation toolsGo to permalink When the Chandra X-ray Observatory celebrates a launch anniversary, it goes big with exploding stars and rotating neutron stars. Today marks 15 years of precision X-ray investigations of stars, galaxies, black holes, neutron stars, and even dark energy. NASA celebrates with supernova and pulsars. Chandra is a space telescope launched on July 23, 1999 on the Space Shuttle Columbia as the heaviest load ever carried into orbit by the space shuttles. From low Earth orbit, it was boosted even farther by the Inertial Upper Stage, a two-stage rocket. Now the spacecraft moseys along in an elliptical orbit, heading out to more than a third of way to the moon at a massive 139,000 kilometers away from the Earth before swinging back around to skim just 16,000 kilometers over the planet. This unusually eccentric orbit allows the spacecraft to put in long observing stints unobscured by Earth's shadow.Advertisement Left: Columbia carrying Chandra into orbit as part of STS-93. Credit: Huntsville Times/Eric Schultz The Chandra X-ray Observatory makes up one fourth of NASA's four Great Observatories, along with Hubble Space Telescope, Spitzer Space Telescope, and the Compton Gamma Ray Observatory. Originally dreamed up under the name Advanced X-ray Astrophysics Facility (AXAF), in 1976, the telescope was renamed to honour the late Indian-American Nobel laureate and astrophysics Subrahmanyan Chandrasekhar before it ever left the planet. The telescope bares his nickname Chandra, which fittingly translates from Sanskrit as "moon" or "luminous." You might recognize his name from astrophysics, as the Chandrasekhar limit is the upper limit on how massive white dwarf stars can be.