In July of 1999, the Space Shuttle Columbia was launched with its heaviest payload to that date. The payload was Chandra, NASA's new X-ray Observatory named after Subrahmanyan Chandrasekhar, one of the most prominent astrophysicists of the twentieth century. The Observatory was deployed by Columbia and then boosted into a high Earth orbit by the satellite's propulsion system. Chandra has a very unusual orbit. Most satellites, including the Hubble Space Telescope, orbit in a low Earth orbit of just a few hundred kilometers altitude. Chandra has an elliptical orbit which takes it more than 138,000 kilometers from Earth and then back to within 9600 kilometers of Earth. Chandra travels more than one-third of the way to the Moon with each orbit! It takes 64 hours and 18 minutes to make one orbit. Because Chandra spends the majority of its orbit above the belts of charged particles which surround Earth, the satellite is able to provide long periods of observing time to astronomers. As of January 2009, Chandra is still in service and providing scientists with an amazing new view of our universe.
Chandra is solar powered and has three major parts. The X-ray telescope contains eight mirrors that focus the X-rays emitted by space objects. The scientific instruments on-board the satellite include a high-resolution camera that records the X-ray images and a spectrometer that determines the energy level of the X-rays. The spacecraft itself provides a safe environment for the telescope and the instruments to work. The telescope is operated by remote control from the Chandra Flight Operations Center at the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts.
Chandra records observations of the universe in the high-energy end of the electromagnetic spectrum. The X-ray images that Chandra records are twenty-five times sharper than previous X-ray images taken by other telescopes. Chandra's extraordinary capabilities make it possible for scientists to study such high-energy objects as supernovae and black holes in greater detail. The satellite has the ability to record X-rays from clouds of gas with temperatures measuring in the millions of degrees. It can also observe gas clouds that are so large it takes light five million years to travel across the cloud. Chandra's resolution is so powerful that you could read a stop sign from a distance of over nineteen kilometers!(Words)
The StarChild site is a service of the High Energy Astrophysics Science Archive Research Center (HEASARC), Dr. Alan Smale (Director), within the Astrophysics Science Division (ASD) at NASA/ GSFC.
StarChild Authors: The StarChild Team
StarChild Graphics & Music: Acknowledgments
StarChild Project Leader: Dr. Laura A. Whitlock
Responsible NASA Official:
If you have comments or questions about the StarChild site, please send them to us.