X-ray astronomy takes hit from lost Astro-E probe
BY JUSTIN RAY
Posted: Feb. 11, 2000
The $105 million Astro-E observatory did not achieve a safe altitude above Earth during its launch on Thursday atop a $62 million Japanese M-5 rocket.
Early indications of what went wrong point to the Institute of Space and Astronautical Science rocket's first stage nozzle, which is suspected of cracking about 40 seconds into flight. Liftoff occurred at 0130 GMT Thursday (8:30 p.m. EST Wednesday) from the Kagoshima Space Center, located on the southern tip of the Japanese island of Kyushu.
The nozzle failure allowed the M-5 to loss its proper orientation during launch. That meant the rocket could not gain enough velocity to place Astro-E into the correct orbit around Earth.
The M-5's second and third stages were unable to make up the lost speed, leaving the observatory in a helpless free fall back into the Earth's atmosphere probably after completing only half an orbit.
Dr. Steven Holt, NASA's project scientist for the Astro-E mission, says his fellow researchers initially thought the launch had been successful.
"We broke out the champagne, literally. We were a little puzzled about why we weren't getting info through the usual sources. It was an hour later before we knew there was a problem."
That red flag indicating a problem came in the form of silence. The Astro-E spacecraft was supposed to establish communications with ground controllers when it passed over a tracking station after completing one orbit of the planet, or 90 minutes after liftoff.
But no signal was received.
Now more than 24 hours after liftoff, U.S. government agencies are still not reporting any objects are in space from this rocket launch. However, as of late Thursday neither Japanese officials nor NASA had publicly announced the Astro-E craft fell from orbit.
Astro-E would have served as the third arm of an X-ray observatory "triumvirate," joining NASA's Chandra and Europe's XMM probe to peer into the universe.
Chandra was launched last July from space shuttle Columbia; XMM atop an Arianespace Ariane 5 rocket in December.
Astro-E was designed to aid Chandra and XMM in performing spectroscopy, studying the "colors" of X-ray light. Astro-E's observations would have offered greater sensitivity and finer colors than ever before.
Astronomers had hoped to use Astro-E to test their theories about the velocities and materials inside super-hot X-ray sources and understand how supermassive black holes, neutron stars and supernova remnants work.
The expected near-term scientific contributions from Astro-E will be heavily missed.
"It is a terrible loss, it is a personal loss," Holt said.
"We will have to struggle by using the other (probes)...but we are not going to wait. We are going to find a way to get this data."
Dr. Nick White, head of the Laboratory for High Energy Astrophysics at NASA's Goddard Space Flight Center that spearheaded the space agency's efforts on Astro-E, said: "This is a devastating loss for the lab, the X-ray group, our colleagues in Japan and for X-ray astronomy."
In a telephone interview Thursday morning Holt said he was already thinking about ways to recover the lost mission and produce the discoveries Astro-E was capable of making.
"It is the right thing to do for science."
Holt has spent the last 20 years working on the cryogenically cooled spectrometer instrument that flew aboard Astro-E. It was originally slated to use aboard the NASA probe that was later scaled back and reborn into the Chandra X-ray Observatory.
Chandra, formerly called the Advanced X-ray Astrophysics Facility, was once a monster space probe. But in the early 1990s, the mission was split into two smaller missions. Congress would later kill the second craft that the featured Holt's spectrometer. NASA then sent the instrument to Japan for use on Astro-E.
Although it took so long to develop the spectrometer's cryogenic detector technologies, Holt says building a replacement won't take another 15 years.
The instrument allows energies of individual X-rays to be measured with a precision about 10 times greater than with previous sensors. Cooling the detector to a temperature of 0.060 degrees Kelvin does this, or about -460 degrees Fahrenheit, making it the coldest object in space.
Astro-E would have also tested the technology for use by the Constellation-X mission currently on NASA's futuristic drawing boards.
Besides the X-ray spectrometer, Astro-E also carried four X-ray imaging instruments, a hard X-ray detector to measure high-energy X-rays and five foil X-ray telescopes.
Flight data file
Launch date: Feb. 10, 2000
Launch time: 0130 GMT (8:30 p.m. EST on 9th)
Launch site: Kagoshima Space Center, Japan
NASA animation of Astro-E shows the spacecraft orbiting the Earth to observe X-ray sources.
PLAY (199k, 20sec QuickTime file)
Dr. Steven Holt talks about advances in X-ray astronomy with Chandra, the X-ray Multi-Mirror satellite and Astro-E.
PLAY (219k, 24sec QuickTime file)
Explore the Net
ISAS - Mission Web site at Japan's Institute of Space and Astronautical Science.
Astro-E Learning Center - Background material on the observatory and its mission.
LHEA - NASA's Laboratory for High Energy Astrophysics where XRS instrument was built.
XIS - MIT home page for the X-ray Imaging Spectrometer instrument.
HXD - Tokyo University home page for the Hard X-ray Detector instrument.
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