Andrew Yee[_1_]
June 4th 08, 05:54 AM
Media Relations
University of California-Berkeley
2 June 2008
Low-cost EUV satellite shut down
By Robert Sanders, Media Relations
BERKELEY -- University of California, Berkeley, scientists quietly switched
off one of the campus's working satellites in April, ending a 10-year series
of ups and downs for NASA's first and only low-cost, university-class
Explorer spacecraft.
The Cosmic Hot Interstellar Plasma Spectrometer satellite (CHIPSat), funded
by NASA in 1998, was designed to look for extreme ultraviolet (EUV)
emissions from the bubble of hot gas that envelops our solar system out to a
distance of several hundred light years.
Five years later, after two cancellations and anxious scrambling for launch
space by Mark Hurwitz, the UC Berkeley physicist who shepherded the
satellite from its original concept, CHIPSat was launched on Jan. 12, 2003.
The total cost was $14.5 million. The only other university-class Explorer
(UNEX) mission approved never made it to launch.
On April 11, 2008, not long after its fifth anniversary in orbit, CHIPSat
was essentially told not to call home anymore.
"It is sad and liberating," said Hurwitz, who, during CHIPSat's lifetime
transitioned from a data-crunching research astronomer to a high school
physics teacher at Lick-Wilmerding High School in San Francisco. "It's been
lucky that the project has gone on as long as it has, and it has been very
cool."
Although the team needed only about $100,000 to operate the satellite
through the rest of 2008, Hurwitz said the budget climate is tight and that
NASA personnel do not have the discretion they had in past years. According
to Patrick Crouse, project manager for space science mission operations at
NASA's Goddard Space Flight Center, CHIPSat is one of five satellites turned
off since last fall, and only two of them had become inoperable.
"Typically, missions just kept getting extended, but we're now reaching the
end of diminishing returns on some of these small satellites," said Crouse,
who still oversees about 20 other satellites for Goddard.
The CHIPS instrument never did detect EUV radiation from the hot
interstellar gas, which may be cooler or hotter than the million-degree
Kelvin temperatures expected, or else theories of what makes up the sparse
material between stars are incomplete. After about three years of operation,
Hurwitz concluded from CHIPS measurements that the EUV glow of the local
interstellar medium was less than one-thirtieth expected, and redirected the
satellite to look at EUV emissions from the sun.
Hurwitz and colleagues at UC Berkeley's Space Sciences Laboratory had hoped
that NASA would be interested in such studies, since they complement the
observations of other satellites studying the sun's ultraviolet emissions.
"CHIPSat's instruments can provide a high-resolution solar spectrum that can
help us learn about the temperature distribution in the sun's chromosphere
and corona and the EUV input to the photochemistry in Earth's upper
atmosphere," Hurwitz said.
Additionally, from an altitude of 575 kilometers, CHIPSat was observing the
so-called "ultraviolet sunset" in the tenuous outer layers of Earth's
atmosphere, probing the distribution of nitrogen and oxygen high above the
surface of the earth. Unfortunately, NASA turned down two proposals to
support such studies.
Hurwitz reminisced about the hurdles he had to overcome to get the CHIPS
instrument launched in the first place. Though the original proposal called
for attaching an extreme ultraviolet spectrograph to a commercial
communications satellite to be launched aboard a Russian rocket, the U.S.
government killed that idea when it unexpectedly applied to the CHIPS
instrument a policy designed to prevent the launch of government-funded
satellites aboard foreign launch vehicles.
"After the Russian rocket fiasco, we pounded the pavement for months,
looking for any way to get our small instrument into space," recounted
Hurwitz. "At the end of the day, we would have done just as well to stand on
the side of the road near the Kennedy Space Center and stick out a thumb."
An offer to piggy-back aboard the launch of a global positioning satellite
(GPS) made Hurwitz and his team scramble to build an independent satellite,
CHIPSat, instead of a ride-along experiment, but that fell through in 1999.
Finally, NASA switched CHIPSat into a Delta rocket to replace a satellite
having problems, and the mini-satellite was launched in 2003.
"Many people at NASA and elsewhere assigned us a low probability of
success," Hurwitz said. The satellite and instrument had been built on a
shoestring, and without the parts qualification and test programs that the
larger projects use. But both the satellite, built by SpaceDev Inc. of
Poway, Calif., and the EUV spectrometer, built at UC Berkeley's Space
Sciences Laboratory (SSL), performed beyond all expectations, he said.
"The operations team at UC Berkeley, led by Mark Lewis and Manfred Bester,
has done a fantastic job over the years keeping an increasingly
temperamental satellite healthy and productive," he said.
CHIPSat has also been productive from an engineering perspective. It was
NASA's first mission to communicate via IP (Internet protocol), and it was
used by NASA's Exploration Initiative to test scheduling systems software in
orbit. A small satellite group at the Ames Research Center in Mountain View,
Calif., used CHIPSat to study real-time data during ground station passes.
"The design life was 18 months because, beyond that, the cumulative effects
of radiation and thermal cycling had a good chance of causing component
failure," said Michael Sholl, CHIPS project manager at the SSL. "But as
happened with some other low-cost missions, once the CHIPS instrument
survived the first few months, it proved to be sufficiently robust for
long-term operations."
The SSL team and NASA both are still open to reviving CHIPSat if the need
arises. Crouse noted that the SWAS (Submillimeter Wave Astronomy Satellite)
spacecraft, which was turned off at the end of January, had been revived
several times previously to make observations of comets and to view the Deep
Impact collision.
"Turning it off does not mean it's unrecoverable," Crouse said. "These
missions were designed so that someone could not accidentally shut them down
forever, so the flip side of that is, it is hard to shut them down forever.
We leave them in a pacified state but, if it was in the interests of the
agency, we could try to recover them and bring them back."
That would have to happen before CHIPS falls from orbit and burns up in a
fiery plunge through the atmosphere.
"The satellite could last five years or longer in orbit, and if NASA wants
to turn it on again, I'd be happy to support that work," Hurwitz said.
IMAGE CAPTION:
[http://www.berkeley.edu/news/media/releases/2008/06/images/CHIPSat.jpg
(12KB)]
CHIPSat satellite (SpaceDev Inc. image)
University of California-Berkeley
2 June 2008
Low-cost EUV satellite shut down
By Robert Sanders, Media Relations
BERKELEY -- University of California, Berkeley, scientists quietly switched
off one of the campus's working satellites in April, ending a 10-year series
of ups and downs for NASA's first and only low-cost, university-class
Explorer spacecraft.
The Cosmic Hot Interstellar Plasma Spectrometer satellite (CHIPSat), funded
by NASA in 1998, was designed to look for extreme ultraviolet (EUV)
emissions from the bubble of hot gas that envelops our solar system out to a
distance of several hundred light years.
Five years later, after two cancellations and anxious scrambling for launch
space by Mark Hurwitz, the UC Berkeley physicist who shepherded the
satellite from its original concept, CHIPSat was launched on Jan. 12, 2003.
The total cost was $14.5 million. The only other university-class Explorer
(UNEX) mission approved never made it to launch.
On April 11, 2008, not long after its fifth anniversary in orbit, CHIPSat
was essentially told not to call home anymore.
"It is sad and liberating," said Hurwitz, who, during CHIPSat's lifetime
transitioned from a data-crunching research astronomer to a high school
physics teacher at Lick-Wilmerding High School in San Francisco. "It's been
lucky that the project has gone on as long as it has, and it has been very
cool."
Although the team needed only about $100,000 to operate the satellite
through the rest of 2008, Hurwitz said the budget climate is tight and that
NASA personnel do not have the discretion they had in past years. According
to Patrick Crouse, project manager for space science mission operations at
NASA's Goddard Space Flight Center, CHIPSat is one of five satellites turned
off since last fall, and only two of them had become inoperable.
"Typically, missions just kept getting extended, but we're now reaching the
end of diminishing returns on some of these small satellites," said Crouse,
who still oversees about 20 other satellites for Goddard.
The CHIPS instrument never did detect EUV radiation from the hot
interstellar gas, which may be cooler or hotter than the million-degree
Kelvin temperatures expected, or else theories of what makes up the sparse
material between stars are incomplete. After about three years of operation,
Hurwitz concluded from CHIPS measurements that the EUV glow of the local
interstellar medium was less than one-thirtieth expected, and redirected the
satellite to look at EUV emissions from the sun.
Hurwitz and colleagues at UC Berkeley's Space Sciences Laboratory had hoped
that NASA would be interested in such studies, since they complement the
observations of other satellites studying the sun's ultraviolet emissions.
"CHIPSat's instruments can provide a high-resolution solar spectrum that can
help us learn about the temperature distribution in the sun's chromosphere
and corona and the EUV input to the photochemistry in Earth's upper
atmosphere," Hurwitz said.
Additionally, from an altitude of 575 kilometers, CHIPSat was observing the
so-called "ultraviolet sunset" in the tenuous outer layers of Earth's
atmosphere, probing the distribution of nitrogen and oxygen high above the
surface of the earth. Unfortunately, NASA turned down two proposals to
support such studies.
Hurwitz reminisced about the hurdles he had to overcome to get the CHIPS
instrument launched in the first place. Though the original proposal called
for attaching an extreme ultraviolet spectrograph to a commercial
communications satellite to be launched aboard a Russian rocket, the U.S.
government killed that idea when it unexpectedly applied to the CHIPS
instrument a policy designed to prevent the launch of government-funded
satellites aboard foreign launch vehicles.
"After the Russian rocket fiasco, we pounded the pavement for months,
looking for any way to get our small instrument into space," recounted
Hurwitz. "At the end of the day, we would have done just as well to stand on
the side of the road near the Kennedy Space Center and stick out a thumb."
An offer to piggy-back aboard the launch of a global positioning satellite
(GPS) made Hurwitz and his team scramble to build an independent satellite,
CHIPSat, instead of a ride-along experiment, but that fell through in 1999.
Finally, NASA switched CHIPSat into a Delta rocket to replace a satellite
having problems, and the mini-satellite was launched in 2003.
"Many people at NASA and elsewhere assigned us a low probability of
success," Hurwitz said. The satellite and instrument had been built on a
shoestring, and without the parts qualification and test programs that the
larger projects use. But both the satellite, built by SpaceDev Inc. of
Poway, Calif., and the EUV spectrometer, built at UC Berkeley's Space
Sciences Laboratory (SSL), performed beyond all expectations, he said.
"The operations team at UC Berkeley, led by Mark Lewis and Manfred Bester,
has done a fantastic job over the years keeping an increasingly
temperamental satellite healthy and productive," he said.
CHIPSat has also been productive from an engineering perspective. It was
NASA's first mission to communicate via IP (Internet protocol), and it was
used by NASA's Exploration Initiative to test scheduling systems software in
orbit. A small satellite group at the Ames Research Center in Mountain View,
Calif., used CHIPSat to study real-time data during ground station passes.
"The design life was 18 months because, beyond that, the cumulative effects
of radiation and thermal cycling had a good chance of causing component
failure," said Michael Sholl, CHIPS project manager at the SSL. "But as
happened with some other low-cost missions, once the CHIPS instrument
survived the first few months, it proved to be sufficiently robust for
long-term operations."
The SSL team and NASA both are still open to reviving CHIPSat if the need
arises. Crouse noted that the SWAS (Submillimeter Wave Astronomy Satellite)
spacecraft, which was turned off at the end of January, had been revived
several times previously to make observations of comets and to view the Deep
Impact collision.
"Turning it off does not mean it's unrecoverable," Crouse said. "These
missions were designed so that someone could not accidentally shut them down
forever, so the flip side of that is, it is hard to shut them down forever.
We leave them in a pacified state but, if it was in the interests of the
agency, we could try to recover them and bring them back."
That would have to happen before CHIPS falls from orbit and burns up in a
fiery plunge through the atmosphere.
"The satellite could last five years or longer in orbit, and if NASA wants
to turn it on again, I'd be happy to support that work," Hurwitz said.
IMAGE CAPTION:
[http://www.berkeley.edu/news/media/releases/2008/06/images/CHIPSat.jpg
(12KB)]
CHIPSat satellite (SpaceDev Inc. image)