  The Chandra X-ray Observatory is the X-ray component of NASA's Great
Observatory Program which includes the recently launched Spitzer Infrared
Telescope, the Hubble Space Telescope (HST) for observations in the visible,
and the Compton Gamma-Ray Observatory (CGRO) which, after providing years of
useful data has reentered the atmosphere. All these facilities provide, or
provided, scientific data to the international astronomical community in
response to peer-reviewed proposals for their use. The Chandra X-ray
Observatory was the result of the efforts of many academic, commercial, and
government organizations primarily in the United States but also in Europe.
NASA's Marshall Space Flight Center (MSFC) manages the Project and provides
Project Science; Northrop Grumman Space Technology (NGST -- formerly TRW)
served as prime contractor responsible for providing the spacecraft, the
telescope, and assembling and testing the Observatory; and the Smithsonian
Astrophysical Observatory (SAO) provides technical support and is responsible
for ground operations including the Chandra X-ray Center (CXC). Telescope and
instrument teams at SAO, the Massachusetts Institute of Technology (MIT), the
Pennsylvania State University (PSU), the Space Research Institute of the
Netherlands (SRON), the Max-Planck Institut fur extraterrestrische Physik
(MPE), and the University of Kiel also provide technical support to the Chandra
Project. We present here a detailed description of the hardware, its on-orbit
performance, and a brief overview of some of the remarkable discoveries that
illustrate that performance.
