NASA To Support European Space Agency's X-Ray Multi Mirror Telescope Mission

NEWS RELEASE -- ISSUED DEC. 10, 1999

American scientists are anxiously awaiting the launch of the European Space Agency's X-Ray Multi Mirror (XMM) spacecraft, set to lift off Dec. 10 from French Guyana on an Ariane 5 launch vehicle.

The XMM spacecraft, an X-ray satellite designed to provide high quality X-ray spectra of X-ray sources from black holes to very hot objects created when the Universe was very young, is a European Space Agency project with contributions from NASA. NASA's involvement in the mission includes provision of critical components for two of the spacecraft's three science instruments and participation in the science-observing program. Based upon the initial competition for observing time, U.S. scientists will receive about one fifth of the observing time on the spacecraft during its first two years in orbit.

NASA's Goddard Space Flight Center (Greenbelt, Md.) provided technical oversight of the U.S. provided hardware that is flying aboard the spacecraft. Goddard also will oversee the U.S. guest observer program wherein selected scientists are awarded observing time on the new observatory to gather science data. Goddard will provide support to U.S. guest scientists in the form of data archives, technical guidance and software support.

"Goddard will be providing support for U.S. scientists using this world class observatory and we are extremely optimistic that this will result in first class science," said Goddard scientist Dr. Richard Mushotzky who is part of the XMM science team.

U.S. hardware co-investigator, Dr. France Cordova from the University of California at Santa Barbara, contributed to the construction of two of the European instruments. Cordova and co-workers provided the data processing unit, the digital electronics modules, software and science support for the Optical Monitor (OM) instrument. Another U.S. co-investigator, Dr. Steve Kahn from Columbia University in New York City, provided two reflection grating assemblies for the Reflection Grating Spectrometer, data analysis software and science support.

"Both of these instruments are state-of-the-art and the Reflection Grating Spectrometer in particular has advanced new technology," said Mushotzky.

The third instrument comprising the science payload, the European Photon Imaging Camera (EPIC), has silicon chips that can obtain medium spectral resolution x-ray spectra from sources much fainter than ever before. The RGS will analyze the spectra in more detail and with greater resolution. The Optical Monitor will observe the same part of the sky as the x-ray telescopes but in the ultraviolet and optical wavelengths. This will give astronomers complementary data on the X-ray sources observed with the EPIC and RGS instruments.

The spacecraft has four telescopes. Three of them are X-ray telescopes with the combined surface area of a tennis field, 120 square meters. However, due to the fact that the x-rays are focussed via reflection at very shallow angles, the effective collecting area for x-rays is 100 times less. In addition to the large collecting area afforded by XMM, the spacecraft will operate in an orbit that will allow it to take long and uninterrupted observations. The fourth telescope is a 30-centimeter optical telescope, which, by virtue of its operation above the atmosphere, is much more sensitive than a similar telescope on the ground.

The name of XMM stems from its multiple mirrors. XMM, with the largest x-ray collecting area flown to date, will allow astronomers to gather and analyze more X-ray sources quicker than with previous space observatories. Scientists expect XMM will explain a number of cosmic mysteries, ranging from black holes to the origin of the universe. XMM will investigate supernova remnants, black holes, magnetically active flare stars and more.

XMM, a world-class observatory, is the second cornerstone mission of ESA's Horizon 2000 program. Its large effective area and soft x-ray spectroscopic capabilities very nicely complement the high angular-resolution and higher energy x-ray spectroscopic capabilities of NASA's recently launched Great Observatory for x-ray astronomy, the Chandra X-ray Observatory. The minimum mission life of the spacecraft is two years but it is expected to last much longer.

Related Web Site:

European Space Agency's X-Ray Multi Mirror (XMM) -- http://xmmlaunch.esa.int/