[meteorite-list] Researchers Chase Victoria's Secret

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Mon Oct 2 11:36:02 2006
Message-ID: <200610021535.IAA13059_at_zagami.jpl.nasa.gov>

http://www.aviationnow.com/avnow/news/channel_awst_story.jsp?id=news/aw100206p2.xml

Researchers Chase Victoria's Secret
By Craig Covault
Aviation Week & Space Technology
October 2, 2006

VICTORIA'S SECRET

The Mars Rover Opportunity is beginning complex and dangerous science
operations 242 million mi. from Earth at the massive Victoria crater,
the most spectacular and potentially significant target of the entire
$800-million twin-rover Mars surface exploration mission.

"We are frankly feeling a little overwhelmed by what we see so far,"
says Steve Squyres, rover principal investigator on his Cornell
University web site.

Opportunity has been driving at the the speed of a tortoise for 5.7 mi.
and almost three years to reach the 2,500-ft.-dia., 230-ft.-deep crater.
Every inch has been a marvel of autonomous robotics and dedicated
command and control by Pasadena, Calif.'s Jet Propulsion Laboratory
(JPL), as well as 24/7 planning by a dispersed international science
battle staff led by Squyres and Deputy Principal Investigator Ray
Arvidson at Washington University in St. Louis. The teams have been
preparing for almost two years for their arrival at Victoria.

>From a position about 8 ft. from the rim, one can see 0.5 mi. to the far
side of the crater, framed by rocky cliffs. The crater's rim comprises
alternating promontories, recessed alcoves and rocky points towering 230
ft. above the bottom of the crater. Martian wind-carved sand dunes cover
the crater floor.

For this Navcam panorama above, colorized by outside analysts,
Opportunity was about 8 ft. from the lip at Duck Bay alcove (see image
right).

The rover has made dozens of sampling stops over the last 21 months. At
the mission's outset, no one dreamed that Opportunity could reach
Victoria, imaged well south of the landing site by the Mars Global
Surveyor orbiter.

"We're so proud of Opportunity, the rover that 'takes a lickin' but
keeps on tickin,'" says Cindy Oda, a Mars rover mission manager at JPL.
"It continues to overcome all challenges despite its aging parts and
difficult terrain. We are looking forward to exciting new discoveries as
Opportunity begins its new adventures exploring Victoria crater."

The trip began in earnest after several months spent in Endurance crater
in mid-2004. The team could hardly believe Opportunity survived that,
let alone reach Victoria, five times bigger than Endurance. Victoria was
carved out much deeper by a large meteorite perhaps more than a billion
years ago. Researchers believe Victoria has the potential for revealing
once deeply buried rock layers as evidence of possibly abundant, perhaps
life-sustaining water. Layers 200-ft. deep may be exposed, compared to
25-ft. layers at Endurance.

Victoria is 40 times larger than Eagle crater, where Opportunity made
initial stunning discoveries in only 1.5-ft. layers about the permanence
of Martian water, which is a key to the formation of life, if it ever
existed, on Mars.

Victoria's secrets are buried in the rock layers; the more layers, the
more detailed the story. "This is a geologist's dream come true," says
Squyres. "Those layers of rock, if we can get to them, will tell us new
stories about the environmental conditions long ago. We especially want
to learn whether the wet era that we found recorded in the rocks closer
to the landing site extended farther back in time. The way to find that
out is to go deeper, and Victoria may let us do that."

Opportunity's arrival at Victoria kicks off a very busy period of Mars
exploration this month involving three U.S. and one European orbiter,
along with preparations for another U.S. lander.

The main events involve:

*The Mars Reconnaissance Orbiter (MRO): The most powerful planetary
imaging spacecraft ever flown is this week in the midst of its initial
high-resolution Mars science-imaging after the completion of aerobraking
to reach its low-altitude science orbit (AW&ST Sept. 25, p. 21).

"This is truly a significant moment for the MRO team," says Jim Graf,
MRO project manager at JPL, which is commanding the spacecraft with
Lockheed Martin near Denver.

MRO's first priority target will be the proposed northern polar region
landing site for the NASA Phoenix lander. Phoenix is less than a year
away from launch to Mars from Cape Canaveral on a mission to dig for
subsurface ice that may hold clues to the potential for life in that
specific environment.

The MRO University of Arizona High-Resolution Imaging Science (HiRISE)
camera, coupled with a suite of other sensors, was to relay its first
low-altitude images Sept. 29 and continue through this week. The
objective is to image the Phoenix site for landing obstructions as early
as possible.

"We want to image it while the area is still fully illuminated," Graf
says. "There is a period of solar conjunction coming when the Sun will
block signals from Mars. If we wait, the imaging will start
degrading--but the Phoenix team needs the data this October."

The imaging through Oct. 6 will also be the first time that MRO will use
its onboard targeting algorithms to point at desired targets on Mars.

*Phoenix: The NASA/University of Arizona Phoenix lander with its
powerful digging arm, developed by Alliance Spacesystems Inc. in
Pasadena, and miniature sample ovens is itself undergoing major hardware
buildup at Lockheed Martin.

*Europe's Mars Express: Mars Express is just emerging from a period
where its solar arrays could not generate power because Mars blocked the
Sun for up to 75 min. at a time. This occurs periodically, but was
especially serious in late September, when complications from an earlier
failure prevented full battery charging even when the Sun was in view.
"This was potentially critical, and we knew we had to devise a solution
that wasn't in the manual," says Michel Denis, Spacecraft Operations
Manager at ESA's Space Operations Center, in Darmstadt, Germany.

Systems were turned off and, at times, the spacecraft pointed away from
Earth and its critical communications link with Darmstadt. The
spacecraft was forced into survival mode. The Mars Express prime
contractor, Astrium, in Toulouse, France, worked closely with ESA,
providing detailed information and conducting a parallel study to
cross-check and verify the survival procedures. The effort worked, and
Mars Express is this week getting back to normal imaging operations.

*Mars Global Surveyor and Mars Odyssey: Global Surveyor, which arrived
at Mars in 1997, and Odyssey, which began specialized imaging in 2001,
are being budgeted for two more years each, says Doug McCuistion, NASA's
Mars Exploration Program director.

Odyssey has also made a remarkable new discovery about Mars. New
analysis of data from its Raytheon Thermal Emission Imaging System,
operated by Arizona State University, has found that violent gas
eruptions occur every spring around the south polar ice cap.

Jets of carbon dioxide erupt at 100 mph. from the ice cap as it warms,
carrying dark sand and dust high aloft. "The dark material falls back to
the surface, creating dark patches on the ice cap, which have long
puzzled scientists," says Phil Christensen of Arizona State University,
principal investigator for Odyssey's camera. "All around you, roaring
jets of carbon dioxide are throwing sand and dust a couple hundred feet
into the air [image top left]."

Both the rovers Spirit and Opportunity are also getting one-year budget
extensions into early 2008.

The original Victoria sailed into exploration history in 1522 as the
only ship under captain Ferdinand Magellan to circumnavigate the globe.
Now, the ship's namesake will be the focal point of at least a year of
rover exploration on the surface of Mars--a mission so important that
Opportunity may spend its final days there, perhaps sacrificing its life
for science in a "crater-to-grave" scenario to reach rock layers so deep
in the crater that the rover may not escape.

But rover drivers at JPL are this week much more concerned about a
"Thelma and Louise" scenario where the rover could fatally drive over
the extremely steep edges of the cliff. It will be navigated as it uses
commands from Earth and its own autonomous robotic navigation to move
slowly near the rim.

Before the trip around the crater, JPL will command the rover to creep
onto a promontory to spend several days taking a highly detailed Pancam
image that will provide scientific data and vivid imagery to map future
operations.

It will also bag major early findings, just in case anything goes awry
on the jagged edge of the crater.

In late September, as Opportunity approached Victoria, the team
performed a crucial software change. On Sept. 20, JPL rebooted the rover
computer after loading the new flight software. Fortunately, the rover
awoke that afternoon with the software functioning normally.

"This new software is going to be a pretty big deal for us," Squyres
says on his web site. "It includes lots of new capabilities, things that
we've figured out over all these sols [Martian days] that we have now
taught the vehicle to do with this software. One capability is 'go and
touch,' the ability to send the rover to a target and deploy the arm
onto that target all in one sol. That's something we've never done on
Mars before. Another is automated dust-devil finding, which should be
pretty cool if Spirit is still hanging in there by summer. And there are
a bunch of other things, too. The rovers are getting older, but they're
suddenly a whole lot smarter," he says.

NASA chose to boot the new flight software when it did because "in a few
weeks we will go into 'superior conjunction,' when Mars goes out of
sight behind the Sun," Squyres says. "There will be a stretch of time
when we can't send commands to the rovers at all, and during that time
we want to have complete, unequivocal confidence in the software that's
on board."

Spirit has also received a new software load. Halfway around Mars and
farther south of the planet's equator, Spirit has been staying at one
northward-tilted position through the southern Mars winter for a maximum
energy supply to its solar panels.

In the meantime, Spirit is conducting studies that benefit from staying
in one place, such as monitoring effects of wind on dust. It will begin
driving again when the Martian spring increases the amount of solar
power available.

When it landed in January 2004, Opportunity, and its twin, Spirit, on
the opposite side of the planet, had specification lifetimes of 90 days
and 2,000 ft. of driving.

Opportunity's ability to survive and reach Victoria far from its
original landing site, and Spirit's ability last year to climb to a
Martian mountaintop, will live long in planetary science and rank among
the great achievements of the U.S. robotic space program.
Received on Mon 02 Oct 2006 11:35:58 AM PDT