Feb. 11, 2000
The prime instrument on Astro-E was the X-ray Spectrometer (XRS), developed jointly by NASA's Goddard Space Flight Center, Greenbelt, Md. and Japan's Institute of Space and Astronautical Science (ISAS). The XRS measures heat created by individual X-ray photons.
Along with the XRS were four X-ray Imaging Spectrometer (XIS) instruments, a collaboration among Japanese universities and institutions and the Massachusetts Institute of Technology Center for Space Research, and the Hard X-ray Detector (HXD), built by the University of Tokyo and ISAS.
Due to a problem with the first stage of the M-5 rocket, Astro-E did not reach orbit. Astro-E was to join the recently launched European X-ray Multi-Mirror Mission (XMM) satellite and NASA's Chandra X-ray Observatory to ring in a new era of X-ray astronomy. The NASA cost for instrument development was $44.9 million.
In terms of science, the loss of Astro-E leaves a void in the understanding of higher-energy X-ray sources, such as galaxy clusters and supernova remnants and of supermassive black holes, which reveal their secrets in the iron atom emissions that Astro-E would have resolved so clearly.
Astro-E was also the test bed for the X-ray calorimeter, a key component in future X-ray missions. The X-ray calorimeter (the sensor part of XRS) is a new technology that measures the heat deposited by incoming X-ray photons. This technology has been tested on balloons. Astro-E was to be the first long-term test in the harsh environment of space.
NASA has cooperated with ISAS on very complex and important space science missions, and planning and work on future missions together continues.
Institute of Space and Astronautical Science
Sagamihara City, Japan
Feb 14, 2000
1. Launch Situation
The M-V-4 was launched at 10:30 a.m. on Feb. 10 (Thu), 2000. The weather was fine, and the surface wind was 1 meter per second NW. The temperature was 8 degrees centigrade.
2. General Description of Flight
M-V-4 flew along the planned trajectory at the early stage, but, at 41 seconds after liftoff, the inner pressure of the first stage motor abruptly dropped. The attitude disturbance much greater than anticipated which occurred at 55 seconds caused the trajectory higher than planned, and resulted in the shortage of the velocity increment at the first stage burnout.
The burning and control of the second and the third stage motors were normal, and strived to restore the velocity deficiency but in vain. As a result, M-V-4 was unable to throw ASTRO-E satellite into planned orbit.
Detailed description on malfunction is now under preparation.
The ASTRO-E mission has been lost. The first stage of the M-V rocket had a serious attitude control problem beginning 42 seconds into the flight. The resulting loss of altitude was too much to be recoverd by the second and third stages. As a result the satellite's orbit was too low. No signal from ASTRO-E was detected, and it is assumed to have reentered and burned up.
Observing the X-ray spectrum of the distant universe, ASTRO-E was to have opened a new window into the workings of black holes, neutron stars, active galaxies, and other very energetic objects. It would have had more collecting area, higher spectral resolution, and wider bandpass than anything that came before.
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T O D A Y
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February 8th, 2000 - Issue #171
NASA Headquarters, Washington, DC
Goddard Space Flight Center, Greenbelt, MD
February 2, 2000
"This new mission allows us to apply a piece of whiz-bang new technology to the exploration of the Universe," said Dr. Alan N. Bunner, Science Director of NASA's Structure and Evolution of the Universe program.
The new instrument is the X-ray Spectrometer (XRS), developed jointly by NASA's Goddard Space Flight Center, Greenbelt, MD, and Japan's Institute of Space and Astronautical Science (ISAS). The XRS measures the heat created by individual X-ray photons, as opposed to converting X-rays to electrical charges and then collecting that charge, which is the mechanism in other X-ray detectors.
Using this new technique, it is possible to measure the energies of individual X-rays with a precision approximately 10 times greater than with previous X-ray sensors. To sense the heat of a single photon, however, the XRS detector must be cooled to an extremely low temperature, only 0.060 degrees Kelvin, or about - 460 degrees Fahrenheit.
This essentially makes the XRS detector the coldest object in space. The absence of all heat, called absolute zero, is 0.0 degree Kelvin; the coldest reaches of space are a balmy three degrees Kelvin.
"This increased precision for measuring X-rays should allow fundamental breakthroughs in our understanding of essentially all types of X-ray emitting sources, especially material very close to black holes and the X-ray emitting gas in the vast spaces between the individual galaxies that make up clusters of galaxies," said Dr. Richard Kelley, XRS Principal Investigator at Goddard.
Astro-E's targets include: clusters of galaxies; supermassive black holes; neutron stars; supernova remnants; stellar coronae of stars 10,000-times more active than our Sun; and a study of the history of how chemicals are made throughout the Universe.
Astro-E is primarily a spectroscopy mission, which means the satellite's instruments will study the "colors" of X-ray light, much like a prism breaks visible light into the colors of the rainbow. While the recently launched Chandra X-ray Observatory excels in producing X-ray images, Astro-E excels in producing spectra. In this regard, Astro-E complements Chandra, analyzing the light that Chandra sees and determining the temperature, velocity and composition of the gas producing those X-rays.
Along with the XRS are four X-ray Imaging Spectrometer (XIS) instruments, a collaboration among Japanese universities and institutions and the Massachusetts Institute of Technology Center for Space Research, and the Hard X-Ray Detector (HXD), built by the University of Tokyo and ISAS. Both the XRS and XIS instruments will analyze X-ray photons focused by individual X-ray telescopes, built at Goddard by a team led by Dr. Peter J. Serlemitsos.
The imaging instrument utilizes detectors similar to those flown on ASCA, Astro-E's precursor, yet with twice the collection efficiency at certain X-ray wavelengths. The Hard X-Ray Detector will extend Astro-E's observation ability into the "hard" or higher-energy X-ray wavelengths with the highest sensitivity ever achieved.
Astro-E will be launched on an M-V rocket from the Kagoshima Space Center, located on the southern tip of the Japanese island of Kyushu. The observatory's expected mission lifetime is five years (two years for the X-Ray Spectrometer, with the depletion of cryogenic gases). Astro-E will attain a near-Earth circular orbit of approximately 341 miles (550 kilometers). Its payload weighs 3,630 pounds (1,650 kilograms), and measures 20.8 x 17.28 x 6.72 feet (6.5 x 5.4 x 2.1 meters).
With its official name to be bestowed after deployment, Astro-E will join the recently launched European X-ray Multi- Mirror Mission and NASA's Chandra X-ray Observatory, ushering in what many experts are calling the decade of X-ray astronomy. Astro-E is the fifth in a series of Japanese satellites devoted to studying celestial X-ray sources. Previous missions are Hakucho, Tenma, Ginga, and ASCA. ASCA, launched Feb. 20, 1993 and formerly known as ASTRO-D, is still active.
More information on the Astro-E mission can be found on the Internet at: