Principal Investigator Claude Canizares
Co-investigator David P Huenemoerder
Project Website http://asc.harvard.edu/cdo/about_chandra/
NASA's Chandra X-ray Observatory, which was launched and deployed by Space Shuttle Columbia in July of 1999, is the most sophisticated X-ray observatory built to date.
Chandra is designed to observe X-rays from high energy regions of the universe, such as hot gas in the remnants of exploded stars. The two images of the Tycho supernova remnant shown below illustrate how higher resolution improves the quality of an image:
The image on the left is from a low-resolution detector on the Einstein Observatory. The image on the right, taken by the High Resolution Imager on the Einstein Observatory, has ten times better resolution, or finer detail (pixel area ten times smaller), than the one on the left. Chandra images will be fifty times better than the image on the right.
The Observatory has three major parts: (1) the X-ray telescope, whose mirrors focus X-rays from celestial objects; (2) the science instruments which record the X-rays so that X-ray images can be produced and analyzed; and (3) the spacecraft, which provides the environment necessary for the telescope and the instruments to work.
Chandra's unusual orbit was achieved after deployment by a built-in propulsion system which boosted the observatory to a high earth orbit. This orbit, which has the shape of an ellipse, takes the spacecraft more than a third of the way to the moon before returning to its closest approach to the earth of 10,000 kilometers (6200 miles). The time to complete an orbit is 64 hours and 18 minutes.
The spacecraft spends 85% of its orbit above the belts of charged particles that surround the Earth. Uninterrupted observations as long as 55 hours are possible and the overall percentage of useful observing time is much greater than for the low earth orbit of a few hundred kilometers used by most satellites.