http://news.yahoo.com/s/space/20061101/sc_space/orbitertolookforlosttomarsprobes
Orbiter to Look for Lost-To-Mars Probes
Leonard David
Senior Space Writer
SPACE.com Wed Nov 1, 8:45 AM ET
A super-powerful camera orbiting Mars may help discover the fate of long-lost
spacecraft that never phoned home after reaching the red planet.
Nov 2, 2006
NASA's Mars Reconnaissance Orbiter (MRO) is now circling that puzzling world,
equipped to assist in determining whether life ever arose on the red planet and
characterize its climate and geology, as well as prepare for future
expeditionary crews to land there.
But another sharp-shooting skill of MRO is catching sight of past probes--craft
that ran into trouble and died in the line of Mars duty. That includes NASA's
gone but not forgotten Mars Polar Lander and the British-built Beagle 2.
MRO is outfitted with an array of equipment, including the High Resolution
Imaging Science Experiment (HiRISE) camera--built to provide the most detailed
view of Mars' surface to date. From Mars orbit, MRO can take zoom-in images of
objects on the surface of the planet, checking out features that are about the
size of a small dining room table.
Ugly ending
NASA's Mars Polar Lander was shot toward the red planet in January of 1999,
only to be lost on December 3 that same year as the probe neared its south pole
exploration target. What truly happened to the craft and its exact whereabouts
remain best guesses.
An investigation of the loss concluded that the most probable cause of the
failure was due to the generation of bogus signals when the craft's legs were
deployed high above the martian landscape. Those spurious signals are thought
to have produced a false indication that the spacecraft's outstretched legs had
actually reached Mars.
That misread of its true altitude may have resulted in Mars Polar Lander
prematurely shutting down its set of descent engines. Then, it is thought, the
craft fell to an ugly ending within Mars' south pole region.
"We'll search for Mars Polar Lander when the lighting conditions are good.
Right now it's too dark down there," said Alfred McEwen, Director of the
Planetary Image Research Lab at the University of Arizona in Tucson, Arizona.
He is MRO's HiRISE principal investigator.
As for when the first opportunity to utilize HiRISE to look for Mars Polar
Lander, McEwen told SPACE.com that he hasn't focused on a time frame as yet.
"It's a matter of both illumination angle and atmospheric conditions."
Seasonal snows
The Mars Polar Lander site is on the edge of polar night right now, as Mars is
not quite half-way through its southern winter, explained Richard Zurek, MRO's
project scientist at the Jet Propulsion Laboratory (JPL) in Pasadena,
California.
Zurek said that even when spring comes again to the southern hemisphere on
Mars--February 8, 2007--the seasonal snows made largely of carbon dioxide ice
will still cover the high southern latitudes. These won't be gone from the area
until the latter part of May of next year, he added.
"Right now, MRO is focusing on the high northern latitudes, providing
information for the Phoenix mission to use in selecting their landing site,"
Zurek told SPACE.com. That will be the main focus for MRO until the end of the
calendar year, he said, as Mars moves into late northern winter and observing
conditions deteriorate over the north polar area.
NASA's Phoenix lander is to be launched next year, the first in a series of
Scout-class spacecraft. It is also a resurrected Mars Polar Lander mission but
this time headed for Mars' water-ice-rich northern polar region.
One busy bird
Early next year the focus will shift to looking at Mars Science Laboratory
(MSL) candidate sites, Zurek pointed out. MSL is a hefty wheeled rover to be
dispatched to the red planet in 2009.
"MRO will look at a few of those even before the end of the year, as southern
spring and summer are seasons when dust suspended in the atmosphere is more
extensive and opaque," Zurek continued. "Of course, unless there is a
planet-encircling storm this year, there will still be good seeing over many
areas, but local activity and regional storms introduce a more random element
and a more diffuse background haze. So, MRO will try to get an early look in
areas that are more prone to obscuring dust activity."
It's clear that MRO is going to be one busy bird as Mars researchers hope to
work through a list of roughly 50 or more Mars Science Laboratory targets prior
to a landing site workshop in October 2007.
Other views
Zurek said that scientists also hope to snag some early views of the Viking
Lander 2 site. That NASA spacecraft successfully set down in Mars' Utopia
Planitia in early September of 1976. Doing so will help calibrate
interpretations of higher latitude data being collected for the Phoenix lander
mission, he said.
"We also hope to get back for a second view of Victoria Crater to pair with the
one just taken in order to produce a stereo image before lighting conditions
change too much," Zurek said. NASA's Opportunity Mars rover has wheeled itself
into position to begin studies of that large feature. The space agency's other
doing-just-fine Mars rover, Spirit, is also a likely target - but one that is
not as urgent as some of the other MRO targets on the "to do" list, he observed.
But first, MRO must focus on the near-term needs of Phoenix and Mars Science
Laboratory, Zurek emphasized. "And second, we should not forget that MRO is
supposed to do more than look at places that we already know. It also seeks new
places that may prove to be even better destinations for future missions and to
test our present understanding with new data as we explore more of the diverse
planet that is Mars," he added.
Beagle 2 wreckage or ?
Similar to the Mars Polar Lander loss was the plight of a British-built Beagle
2 probe. It was deployed from the European Space Agency's Mars Express on
December 19, 2003. Mars Express remains busy at work as it orbits the planet.
Beagle 2 was targeted to land in Isidis Planitia via parachutes and airbags to
cushion its touch down. The probe was a science instrument-packed 152 pound (69
kilogram) device that never uttered a peep from the surface of Mars.
"Depending on our success with Mars Polar Lander--and with landers with fairly
well-known locations--we will eventually try for Beagle 2, but that is a much
greater challenge due to its smaller size and the greater uncertainty of its
landing ellipse," Zurek said, noting that his opinions are his own and do not
represent the view or policy of JPL.
Indeed, it might be a stretch for MRO to spot Beagle 2 as it is only a few feet
wide.
Late last year, Beagle 2 wreckage was thought found in imagery relayed from
NASA's Mars Global Surveyor - claimed by some to show that the craft came close
to success. But others in the Mars photo-interpretation community contend that
no incontrovertible evidence exists in imagery to support Beagle 2 being
discovered.
Resolution resolve
"MRO may hopefully resolve what happened to Beagle 2," explained Mark Sims, the
project's mission manager at the Space Research Center's Department of Physics
and Astronomy, University of Leicester in the United Kingdom.
MRO has enough resolution to perhaps directly image the lander and certainly
enough to image any debris or components, like airbags, parachutes, etc. That
is, assuming that such gear is not covered by dust. Now nearly three years
after Beagle 2's landing, hardware dusted over may no longer be recognizable,
Sims told SPACE.com.
"We understand that the HiRISE team intends to image the Beagle 2 landing
ellipse at some point in the mission," Sims said. However, for obvious reasons,
he added, doing so is not a high priority for MRO, given top-of-the-checklist
need to image sites for Phoenix, Mars Science Laboratory, and other future
missions.
"We, however, look forward to what MRO might detect as it would be good to
ascertain how close to a successful landing Beagle 2 came," Sims noted.
Mineral fingerprint
Using MRO as a spotter scope for vanished Mars probes is on the schedule. But
the spacecraft also totes another "eye spy" device for finding spacecraft gone
astray.
Along with HiRISE, MRO's Compact Reconnaissance Imaging Spectrometer for Mars
(CRISM) is now up and operating too. It is able to identify minerals on the
surface of Mars and is one of six science instruments aboard MRO. CRISM
investigations are being led by the Johns Hopkins University Applied Physics
Laboratory in Laurel, Maryland.
Spacecraft hard landings, like in the case for Beagle 2, can churn up a rather
large area of soil in the process. CRISM might locate signs of different
minerals in the upturned crash spot that don't match those of the surrounding
terrain.
JPL's Zurek said that this kind of CRISM data would be like having a mineral
fingerprint pointing to the spot where Beagle 2 plopped down.
a.. Images: Visualizations of Mars
b.. VIDEO: Getting There - MRO's Trip to Mars
c.. Top 10 Facts About NASA's Mars Reconnaissance Orbiter
d.. New Mars Orbiter: Preview of Coming Attractions
e.. Mars in 3-D: Images from Mars Express
a.. Original Story: Orbiter to Look for Lost-To-Mars Probes
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