- MSNBC - NASA's plans for its 21st-century exploration of Mars have been up
in the air for weeks, due to questions about budget and mission priorities.
But the plans are finally taking shape: A clone of the Mars Pathfinder
rover could fly aboard the 2001 probe, and the 2003 probe might even get
a head start on sending samples back to Earth from the Red Planet.
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- THE 2001 AND 2003 Surveyor missions have
been in flux for most of the summer - primarily because of concerns over
whether a next-generation rover known as the Athena would be ready in time
for the 2001 mission. The Athena is a bigger, more versatile version of
the Sojourner rover that made such a hit during the Mars Pathfinder mission.
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- There were also concerns about whether
the mission plans were too ambitious for the funding levels set for Mars
exploration. The series of probes being prepared by NASA's Jet Propulsion
Laboratory build to a climax in 2005: That's when NASA would launch a mission
aimed at gathering a sample of Martian soil and rock and bring it back
to Earth. Scientists would subject such a sample to intensive tests, to
glean information about Mars' evolution and perhaps even determine if the
planet ever sustained life.
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- Two developments have resolved the main
questions surrounding the 2001 and 2003 missions: NASA delayed flying the
first Athena rover until 2003, and Congress approved millions of dollars
of extra money for Mars.
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- Wayne Lee, mission planner for the Mars
exploration program at JPL, said there was enough money to fly a carbon
copy of Pathfinder's Sojourner rover, nicknamed Marie Curie. He said NASA
was proceeding with the engineering analysis for including Marie Curie
on the 2001 probe, "but it has not been officially determined that
it's going ahead."
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- "In terms of congressional funding,
we are getting everything that we're expecting to get," he said. "The
interesting issue comes with Mars that there are just so many great things
to take part in that you can never hope to do everything that you want
to do."
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- A package of scientific instruments known
as the Mars Environmental Compatibility Assessment - which had been in
limbo - also will be aboard the 2001 lander after all, said Thomas Pike,
who is developing the instrument package at JPL. Pike said his team was
working at a frantic pace.
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- "The problem has been that there
was a hiatus of a couple of months because of the funding, but the launch
isn't going to wait a couple of months," he said.
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- MECA will test Martian soil for toxicity
and other qualities that might be harmful to humans. The instruments also
could detect the signature of life forms, although Pike and other researchers
say that would be an extremely long shot.
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- Other experiments on the 2001 mission
will measure surface radiation and test concepts for manufacturing fuel
from Martian ingredients.
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- DEBATE OVER 2003 MISSION
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- NASA spokesman Douglas Isbell said the
general outlines of the 2003 mission should be clear by the end of September.
That mission could be more controversial than 2001 - not because it will
be the first application of the Athena rover, but because it could take
the first concrete step toward the crucial mission in 2005 to return Martian
samples to Earth.
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- Here's one of the scenarios under consideration,
as described by Isbell and Lee:
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- The 2003 spacecraft would include a solid-fuel
ascent vehicle. Martian samples retrieved by the Athena rover would be
loaded aboard the vehicle, then launched into orbit.
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- The 2005 mission would launch a lander,
rover, orbiter and another ascent vehicle toward Mars aboard a French Ariane
5 rocket. This mission would repeat the 2003 routine at a different site
meaning that there would be two ascent vehicles circling Mars, ready to
rendezvous with the orbiter. Mission planners could choose the most promising
sample, or perhaps even both samples, and arrange a linkup with the orbiter.
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- Finally, the orbiter would rocket its
way back toward Earth, re-entering the atmosphere and touching down in
a secure area in 2008.
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- The last part of that scenario is what
has some people concerned. Barry DiGregorio, author of the book "Mars:
The Living Planet," says data from the Viking spacecraft indicate
that Mars may harbor living organisms " and he argues that much more
testing should be done on Mars or in space before samples are brought back
to Earth itself.
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- "We may find that it could be a
deadly situation," he said. It would be safer to set up a quarantine
laboratory on the International Space Station or even on a space shuttle,
he said.
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- On Friday he said he would organize an
effort to oppose the Mars sample return mission with the assistance of
other researchers.
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- PLANETARY PROTECTION
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- Most experts agree that protecting Mars
and Earth from cross-contamination will require special measures. Last
year, a National Research Council study determined that there was a slim
chance that a Martian sample might contain living organisms. The study
said such samples should be physically and biologically isolated and "treated
as though potentially hazardous until proven otherwise."
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- Experts representing NASA, the Centers
for Disease Control and Prevention and other groups are discussing what
kinds of precautions would be adequate.
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- "There's so much technology that
has to be put into making sample return work, if we don't start now we're
not going to make it," JPL's Lee said.
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- The planners say the planetary protection
process would likely require an environmental impact statement, international
consultation, public awareness efforts and detailed technical planning.
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- "We still have a couple of years
on that," Isbell said.
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- Among other developments in Martian exploration:
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- *Detection Limit, based in Laramie, Wyo.,
says it is developing an experimental package for the Surveyor 2003 mission
under an $850,000 NASA contract. The Raman spectroscopy probe would be
designed to show how chemical elements are combined on Mars and could even
determine whether lifelike structures exist, according to a Detection Limit
news release.
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- Raman spectroscopy analyzes the scattering
of light from the molecules that make up a sample, yielding the "fingerprint"
of the molecules. According to Detection Limit President Christian Schoen,
the technique has been use to detect hemoglobin molecules within a tyrannosaur
fossil.
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- JPL's Wayne Lee cautioned that the Athena
rover was currently the only scientific package assured of a spot on the
2003 mission. Other experiments are yet to be selected. "Right now,
just because people are participating in studies doesn't mean that they
will be selected," Lee said.
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- *Mars Global Surveyor, an orbiter currently
circling the Red Planet, has been successful in an effort to take pictures
of the Martian moon Phobos and those new images are due for release in
the first half of September, Lee said.
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- Send your comments to Space News Editor
Alan Boyle at alan.boyle@msnbc.com.
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