A
super-powerful camera orbiting Mars may help discover the fate of long-lost
spacecraft that never phoned home after reaching the red planet.
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.
advertisement
