This story was updated at 4:24 p.m.
EDT.
NASA's Mars
rover Spirit is experiencing the robotic high life--literally--now that it has
reached to top of Husband Hill after a slow, year-long climb.
Perched
some 270 feet--about the height of the Statue of Liberty--above the plains of its
Gusev Crater landing site, Spirit has returned images
of stunning new vistas that include a potential winter refuge as the Martian
seasons progress, mission scientists said Thursday during a press conference at
NASA's Washington, D.C. headquarters.
"That's no
Mt. Everest, but it's a heck of a climb for our little rover," Steve Squyres, principal investigator of the rover's science
mission at Cornell University in Ithaca, New York, told reporters. "When we
first touched down at Gusev Crater on Jan. 4, 2004,
the Columbia Hills looked impossibly far away."
Spirit
spent 591 Martian days roving across the 1.5 miles (three kilometers) between
its landing point and the summit of Husband Hill, one of a network of rises in
the Columbia Hills chain. One Martian day, or sol, is about 24 hours and 40
minutes.
The rover reached
the base of the Columbia Hills, a chain named after the lost STS-107
astronauts--in June 2004. The layered rocks, which Spirit later found were
changed by water in the planets ancient past, and tricky terrain were a welcome
change for researchers, who until then found almost nothing but the same,
basalt rocks--the most basic type of rock--day after day of exploring Gusev Crater.
"The rocks
in the Columbia Hills are nothing like the basalt on the plains," said Ray Arvidson, deputy principal scientist for the rover science
mission at Washington University in St. Louis, Missouri, during the press
conference. "Water was involved in practically every one that we've seen so
far."
Squyres
said Spirit engineers and researchers will spend the next week to 10 days
discussing when to leave the summit, though the rover will likely not stay
atop Husband Hill for many months.
Researchers
have already picked out a long-distance target dubbed Home Plate
in basin to the south of Spirit's current location. A north-facing slope on the
side of another hill, known as McCool Hill, may offer a prime spot to weather
the Martian winter since the rover's solar arrays would be angled toward the
Sun to collect the most sunlight.
"The
deciding factor will be how good the geology is," Squyres
said of the time it will take to descend Husband Hill. "I think going downhill
has the potential to go a bit faster, it's easier to go downhill with these
vehicles than going up."
Opportunity's Rind
While
Spirit took the high road at Gusev, its robotic twin
Opportunity has made steady progress across the rocky etched terrain of Meridiani Planum on the other
side of Mars.
Despite a
still unexplained software glitch, in which Opportunity reset itself on Aug.
21, the rover has given researchers their first glimpse into an odd coating - known
as a 'rind' - that covers some rocks at Meridiani.
"We've been
very curious to figure out what they are," Squyres
said.
Opportunity
used its robotic arm-mounted microscopic imager and rock-grinding abrasion tool
to compare a bare rock dubbed "Strawberry" with a coated area called "Lemon
Rind." While essentially identical in most respects, Lemon Rind contains higher
levels of sodium and chlorine than Strawberry.
"One
possibility is that it's the last layer to form," Squyres
said of Lemon Rind's coating, adding that the rind may also have formed much
later, after both rocks were deposited at Meridiani.
"It speaks to yet another water episode."
Engineers
have slowly been recertifying Opportunity since the software reset even as it
continues its science operations, researchers said.
"I think
the reset itself was more of an annoyance," said Jacob Matijevic,
who heads the rover engineering team at NASA's Jet Propulsion Laboratory (JPL).
"I'd sure like to know what exactly took place."
Spirit and
Opportunity are currently funded through December 2006, with scientific targets
set in six-month sections, NASA's Mars Exploration Program chief Doug McCuistion said.
While the
rovers show some signs of age - the rock grinding bits of Spirit's rock
abrasion tool are so worn, they're only useful for brushing targets clean--they
are still generating ample supplies of power, rover handlers said.
"As long as
these vehicles remain healthy and continue on their science return we'll
continue," McCuistion said. "An asset on the
[Martian] surface like this is invaluable...and we certainly don't want to cut
them off.
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