Text courtesy of NASA

Like all X-ray telescopes, Constellation-X must be positioned in space because X-ray light does not penetrate the Earth's atmosphere. Yet, in designing Constellation-X, scientists wanted an X-ray telescope similar to the large Earth-bound telescopes to collect as much X-ray light as possible. These requirements led to the Constellation-X's unique multi-satellite design. The four satellites are light enough to be launched individually or in pairs, yet combine to provide a sensitivity 100-times greater than any past or current X- ray satellite mission. Essentially, scientists will be able to collect more data in an hour than they would have collected in days or weeks with current X-ray telescopes. We will learn about thousands of faint X- ray emitting sources, not just the bright sources available to us today.

This is Constellation-X looking at E0102-72; Courtesy of NASA

The multi-satellite design also saves money and reduces risk. It is less expensive to build and launch smaller, identical telescopes. And with separate launches for individual telescopes - or perhaps for pairs of telescopes, if the design permits - we avoid putting all our eggs in one rocket, so to speak.

Constellation-X is modeled after the Keck Observatory, twin optical telescopes each 10 meters (33 feet) wide, positioned high atop Mauna Kea in Hawaii. Both observatories have superior collecting areas, or apertures, for analyzing the components of light. Both Keck and Constellation-X are the complements to the great high-angular-resolution space telescopes: the Hubble Space Telescope and the Chandra X-ray Observatory, respectively. No single telescope can do it all. Hubble, along with its many excellent features, provides fantastic images of distant galaxies with unprecedented clarity. The Earth-based Keck supports Hubble, however, by collecting enough light waves to study the gas in those distant galaxies. Likewise, the Chandra Observatory, to be launched by the year 2000, will have the best imaging resolution of any X-ray telescope so far. Scientists will then use the unparalleled data from Constellation-X together with Chandra in analyzing X-ray light and forming a more complete picture of the X-ray Universe.

Constellation-X will document these objects and regions with images, and, more importantly, with spectra. Spectra, the soul of Constellation-X, are like the fingerprints of elements in far-away stars and dusty clouds of hot gas. These diagrams of spectral energy patterns can reveal almost every characteristic of a distant gas, solely from the light it emits. With high- resolution X-ray spectroscopy, we can zoom in to within a few kilometers of the border of a black hole, as close to the black hole itself as any observations can theoretically get. Spectra can be used to see how extreme gravity around a black hole affects the composition, pressure, density, temperature and velocity of the gas swirling into it. Spectra of black holes, supernova remnants and galaxy clusters provided by Constellation-X will be the next best thing to reaching out and touching these objects with our hands.