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NASA has
ordered the Mars rover Opportunity to leave a giant crater it had been studying
for nearly a year over concerns it might not be able to climb out at a later
date.
Engineers noticed a power surge in the rover's left front wheel, and are concerned the surge may be a warning sign of the wheel's eventual failure, NASA said Tuesday. Opportunity's twin, Spirit, lost function in its right front wheel after a similar surge in 2006.
Each rover has six wheels. NASA said Spirit showed the rovers can move on flat terrain with five working wheels, but it is less confident Opportunity would be able to climb out of its current position in the crater if it lost the use of one of its wheels.
Opportunity entered the 800-metre wide Victoria Crater on Sept. 11, 2007, after a year of scouting from the rim. The rover explored the crater, taking images of the exposed layers of ancient rock.
Its next mission will be to study loose fist-size rocks on the equatorial plains of the planet.
The two rovers landed on Mars in 2004 and have remained operational well beyond their original 90-day mission, though both rovers have lost functionality in some of their components.
It costs NASA about $20 million US annually to keep the rovers running. Worth every penny to have a 'set of eyes' on Earth's closest neighbor, Scotty would have been proud.
WASHINGTON — Democratic presidential candidate Barack Obama's position on space exploration continued to evolve Sunday as the Illinois Democrat endorsed a congressional plan to add $2 billion to NASA's budget and agreed to back at least one more space shuttle mission.
In a policy paper released Sunday by his campaign, the presumptive Democratic nominee said his goal was to "minimize the gap" between the end of the shuttle program and the beginning of future manned missions. He also said he was hoping "to ensure retention of" thousands of NASA workers in Texas and Florida whose jobs are threatened by a possible five-year gap before the beginning of the Constellation initiative to send astronauts to the moon and Mars.
The additional NASA funding and shuttle mission are being pushed strongly by Democrats and Republicans from the two states. Obama's Republican opponent, Arizona Sen. John McCain, has already endorsed closing the five-year gap. President Bush opposes the $2 billion in funding, saying it would be fiscally irresponsible.
Obama has not always been a strong supporter of additional money for NASA. Indeed, in December 2007, his campaign Web site declared that he would finance an early childhood education initiative by reducing funding for the Constellation program. And Obama told the Houston Chronicle's editorial board in February that he was not convinced that human exploration was worth the cost.
After Democrats from Florida and Texas complained, Obama pivoted and found other ways to fund his education initiative.
"To his credit, he changed that position," Florida Sen. Bill Nelson said Sunday.
Republicans on Sunday ridiculed Obama's latest statement and said he is pandering to voters to remain competitive in the swing state of Florida, home to the Kennedy Space Center.
"Obama's shifting stance on space exploration is indicative of his inexperience on issues important to voters," said Republican National Committee spokesman Alex Conant. "Let's be honest: Obama is only embracing NASA now because of his political problems in Florida."
McCain told the Houston Chronicle earlier this year that he viewed manned spaceflight as "something that is elemental and a vital part of our space program." He said he wants to close the gap in manned spaceflight, but added, "I think we've got to sort out our priorities better. In other words, we can't do everything."
Obama echoed those thoughts in a statement released by his campaign Sunday. McCain's Democratic opponent declared that he hoped "to maintain a robust program of human space exploration and ... continue our nation's pre-eminence in space."
While Obama endorsed a "balanced program of space exploration and scientific discovery," his policy statement did not include any specific mention of the Constellation program. It did, however, discuss in great detail his support for expanding NASA's robotic and aeronautic programs.
He also proposed to restore a national aeronautics and space council, a group including NASA, the Department of Defense, the Department of Transportation and other air and space stakeholders.
The most important change in Obama's past positions is that he now favors at least one additional space shuttle mission before the shuttles are retired. Florida Sen. Nelson said Obama's staff assured him the presidential candidate favors the congressional plan to add $2 billion to NASA's budget.
Obama's newly released details impressed former astronaut and Sen. John Glenn, D-Ohio. But Glenn, a former space policy adviser to Obama primary rival Hillary Clinton, said he wants more from his candidate. "I hope it goes even further," Glenn said. "At least ... one (more) additional shuttle flight."
Republicans remained skeptical. "Considering Obama's shifting positions, he cannot be trusted to fully support NASA's mission to Mars," said the RNC's Conant. "The only thing Barack Obama knows about sending a man to the moon is that it's a good applause line."
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Old Mars - Geologists say it was once soggy, warm, habitable
Nearly 4 billion years ago much of the surface of Mars was like a soppy carpet. The planet was covered by a thick atmosphere, and it was warm but not exactly picturesque. Those conditions, an international team of three dozen scientists has concluded, could have supported primitive forms of life.
But over time — some 800 million years — Mars dried up and took on the rocky, desert-like appearance that exists today. The scientists' findings, which appear in today's edition of the British journal Nature, are based on mineralogy data collected by the Reconnaissance Orbiter, a U.S. spacecraft that has circled the Red Planet since March 2006.
NASA launched the vessel as the centerpiece of a $720 million mission to examine the planet's rugged terrain and atmosphere. The spaceship's powerful cameras and spectrometer, which examined the Martian geology on a global scale, found a widespread presence of water-borne minerals, called phyllosilicates, throughout the planet's southern highlands.
The claylike minerals were distributed over nearly half the planet. Other regions of Mars, which may have the same mineralogy, are covered with more recent lava flows.
The Reconnaissance Orbiter found the aqueous minerals bonded to iron, magnesium and aluminum on the sides of canyon walls and rocky soils, which had come to the surface after impacts of meteors and comets. The data suggested the ancient Martian surface was soaked in water for several miles below the surface.
"It was like a saturated crust, that is what created the mineralogy," said John Mustard, a Brown University planetary geologist who led the study. Mars and the other planets in the solar system were born about 4.6 billion years ago. During the planet's early water-logged era, Mars would have been a warmer realm with a thicker atmosphere.
"That would have been a habitable environment in my opinion," Mustard said. "When we talk about what would have been habitable," he said, "we all picture pristine lakes and streams and a beautiful mountain environment. In fact, a soppy wet crust is equally viable and perhaps more viable for primitive life."
During an era that lasted less than a billion years, much of Mars may have resembled the geyser-rich Yellowstone National Park. Volcanoes would have been active, craters created by frequent impacts from meteors would fill with water.
The observations with the Reconnaissance Orbiter built on those made by the European Space Agency's Mars Express, which swung into orbit in late 2003. They expanded the discovery of a few dozen sites with water-borne mineralogy to between 5,000 and 10,000 of the locales, said Scott Murchie, a planetary geologist at the Johns Hopkins University's Applied Physics Laboratory and the principal investigator for the spacecraft's spectrometer.
"They are scattered in places where there previously had not been any detection of rocks altered by water. That makes it not so much a localized event but a regional or global event," Murchie said.
"That has huge implications for the potential habitability because it shows that liquid water was more widespread and longer lasting than had been thought," he said. The kind of life would likely have been no more sophisticated than microbial — small organisms able to draw energy and nutrients from the sun and simple chemical reactions within their wet environment.
The findings complement those of Spirit, one of two golf-cart-sized NASA rovers probing the rocks and soil of Mars for more than four years. Climbing a hilly region of Gusav Crater, Spirit found evidence of salts and other mineral residues left behind as the planet's crust began to dry up.