Japanese-U.S. X-ray satellite launch postponed again
Artist's depiction of the Astro-E X-ray telescope
(CNN) -- Japan on Wednesday again postponed the launch of an
observation satellite, this time because of a radar malfunction.
It was the second delay of the launch via M-5 rocket which was
originally planned for 10:30 a.m. Tuesday (0130 GMT), said
Yoshihisa Nemoto, a spokesman for the Institute of Space and
Tuesday's launch of the Astro-E research satellite was postponed
because of bad weather. Nemoto said it has now been rescheduled for
the same time Thursday from the Kagoshima Space Center in
The Astro-E spacecraft carries an X-ray sensor that can
measure remote radiation levels ten times more precisely than
Besides showcasing an entirely new technology in X-
ray detection, the Japanese-U.S. satellite observatory
will earn the distinction of being the coldest known object
"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 and Japan's
Institute of Space and Astronautical Science.
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.
To sense the heat of a single photon, the XRS detector must
be cooled to an extremely low temperature, only 0.060 degrees
Kelvin, or about -460 degrees Fahrenheit.
This condition 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 3 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," said Dr. Richard
Kelley, XRS principal investigator at Goddard, which is based
in Greenbelt, Maryland.
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 the Sun, and a
study of how chemicals are made throughout the universe.
While the Chandra X-ray Observatory, launched in July, excels
in producing X-ray images, Astro-E excels in producing
spectra, or the "colors" of X-ray light. 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.
Besides Astro-E and Chandra, the European X-ray Multi-Mirror
Mission went into orbit in December. The flurry of launches
is ushering in what many experts are calling the decade of X-
Chandra image suggests a traffic jam surrounds black hole
December 10, 1999
Chandra reveals X-ray jet in nearby galaxy
October 26, 1999
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