NASA rejoins Japan in X-ray space observatory project
Posted: July 29, 2001

The United States and Japan will team up to rebuild and launch a powerful observatory for measuring high energy phenomena in the Universe.

The Astro-E2 observatory will replace the original Astro-E satellite, which was lost during launch in February 2000. The Japanese government recently approved the Astro-E2 mission and has invited NASA to participate.

"The opportunity to support the rebuilding of the Astro-E observatory provides NASA with an excellent path for completing the ambitious goals of this program," said Dr. Alan Bunner, Science Director of NASA's Structure and Evolution of the Universe program.

Scheduled for launch in February 2005, the instruments on Astro-E2 will provide powerful tools to use the Universe as a laboratory for unraveling complex, high-energy processes and the behavior of matter under extreme conditions. These include the fate of matter as it spirals into black holes, the nature of supermassive black holes found at the center of quasars, the 100 million degree gas that is flowing into giant clusters of galaxies, and the nature of supernova explosions that create the heavier elements, which ultimately form planets.

NASA will provide the core instrument, the high resolution X- Ray Spectrometer (XRS). The XRS will be the first X-ray microcalorimeter array to be placed in orbit. It measures the heat created by individual X-ray photons.

The XRS operates at a temperature of 65 mK, which is about -459.6 F, only 1/10 degree above absolute zero, and is held at this temperature by a three stage cooling system developed jointly by NASA's Goddard Space Flight Center, Greenbelt, MD, and the Institute of Space and Astronautical Science in Japan. The cryogenic system is capable of maintaining the temperature of the microcalorimeter array for about two years in orbit.

Japan will provide the other instruments on Astro-E2, a set of four X-ray cameras and a high-energy X-ray detector. NASA will also provide the five X-ray telescopes required to focus X- rays on the XRS and the X-ray cameras.

"This increased precision for measuring X-rays should allow fundamental breakthroughs in our understanding of essentially all types of X-ray emitting sources," said Dr. Richard Kelley, principal investigator for the U.S. participation of Astro-E2 at Goddard. "This will be especially true of matter very close to black holes and the X-ray emitting gas in clusters of galaxies."