Sunday, August 5, 2012

Opportunity still plugging away

  • The Mars rover Opportunity has survived eight and a half years on Mars
  • The 5-foot craft was designed to last 90 days
  • "We've taken great care" in operating it, former driver says

(CNN) -- In more than eight Earth years, NASA's unexpectedly tough Mars rover Opportunity has been stuck in a sand dune, nursed a bad shoulder and endured five brutal winters on Mars.

Its new rover, Curiosity, should be so lucky.

Scientists at the space agency's Jet Propulsion Laboratory in California planned for Opportunity to last for 90 days on Mars after its landing in 2004. Instead, it's now run for more than 3,000 martian days and traversed 22 miles of the planet's surface -- scoured by sandstorms and working through temperatures that range from 86 degrees to 112 degrees below zero Fahrenheit (30 to -80 C).

"The rovers were designed to last in extreme conditions, and we've taken great care in how to operate them," said JPL roboticist Vandi Tompkins, one of Opportunity's former operators. "Someday, some essential part will go that stops it. It's going to happen. But we try our best to push that as far as out as we can."

NASA's Mars Curiosity Rover, shown in this artist's concept, is scheduled to touch down on the planet on August 6. NASA's Mars Curiosity Rover, shown in this artist's concept, is scheduled to touch down on the planet on August 6.
Water-ice clouds, polar ice and other geographic features can be seen in this full-disk image of Mars from 2011. Water-ice clouds, polar ice and other geographic features can be seen in this full-disk image of Mars from 2011.
This image was captured in 1976 by Viking 2, one of two probes sent to investigate the surface of Mars for the first time. NASA's Viking landers blazed the trail for future missions to Mars.This image was captured in 1976 by Viking 2, one of two probes sent to investigate the surface of Mars for the first time. NASA's Viking landers blazed the trail for future missions to Mars.
The Valles Marineris rift system on Mars is 10 times longer, five times deeper and 20 times wider than the Grand Canyon. This composite image was made aboard NASA's Mars Odyssey spacecraft, which launched in 2001.The Valles Marineris rift system on Mars is 10 times longer, five times deeper and 20 times wider than the Grand Canyon. This composite image was made aboard NASA's Mars Odyssey spacecraft, which launched in 2001.
The Nili Fossae region of Mars is one of the largest exposures of clay minerals discovered by the OMEGA spectrometer on Mars Express Orbiter. This image was taken in 2007 as part of a campaign to examine more than two dozen potential landing sites for NASA's new Mars rover, Curiosity, also known as the NASA Mars Science Laboratory.The Nili Fossae region of Mars is one of the largest exposures of clay minerals discovered by the OMEGA spectrometer on Mars Express Orbiter. This image was taken in 2007 as part of a campaign to examine more than two dozen potential landing sites for NASA's new Mars rover, Curiosity, also known as the NASA Mars Science Laboratory.
NASA's Mars Phoenix Lander descends to the surface of Mars in May 2008. Less than half of the Mars missions have made successful landings.NASA's Mars Phoenix Lander descends to the surface of Mars in May 2008. Less than half of the Mars missions have made successful landings.
Phoenix's robotic arm scoops up a sample on June 10, 2008 -- the 16th Martian day after landing. The lander's solar panel is seen in the lower left.Phoenix's robotic arm scoops up a sample on June 10, 2008 -- the 16th Martian day after landing. The lander's solar panel is seen in the lower left.
In 2006, NASA's Mars Exploration Rover Spirit captured a 360-degree view known as the McMurdo panorama. The images were taken at the time of year when Mars is farthest from the sun and dust storms are less frequent.In 2006, NASA's Mars Exploration Rover Spirit captured a 360-degree view known as the McMurdo panorama. The images were taken at the time of year when Mars is farthest from the sun and dust storms are less frequent.
The European Space Agency's Mars Express captured this view of Valles Marineris in 2004. The area shows mesas and cliffs as well as features that indicate erosion from flowing water.The European Space Agency's Mars Express captured this view of Valles Marineris in 2004. The area shows mesas and cliffs as well as features that indicate erosion from flowing water.
This view is a vertical projection that combines more than 500 exposures taken by Phoenix in 2008. The black circle on the spacecraft is where the camera itself is mounted.This view is a vertical projection that combines more than 500 exposures taken by Phoenix in 2008. The black circle on the spacecraft is where the camera itself is mounted.
A portion of the west rim of the Endeavour crater sweeps southward in this view from NASA's Mars Exploration Rover Opportunity in 2011. The crater is 22 kilometers (13.7 miles) across.A portion of the west rim of the Endeavour crater sweeps southward in this view from NASA's Mars Exploration Rover Opportunity in 2011. The crater is 22 kilometers (13.7 miles) across.
A photo captured by NASA's Mars Global Surveyor in 2000 offers evidence that the planet may have been a land of lakes in its earliest period, with layers of Earth-like sedimentary rock that could harbor the fossils of any ancient Martian life.A photo captured by NASA's Mars Global Surveyor in 2000 offers evidence that the planet may have been a land of lakes in its earliest period, with layers of Earth-like sedimentary rock that could harbor the fossils of any ancient Martian life.
A U.S. flag and a DVD containing a message for future explorers of Mars, science fiction stories and art about the planet, and the names of 250,000 people sit on the deck of Phoenix in 2008.A U.S. flag and a DVD containing a message for future explorers of Mars, science fiction stories and art about the planet, and the names of 250,000 people sit on the deck of Phoenix in 2008.
A rock outcrop dubbed Longhorn and the sweeping plains of the Gusev crater are seen in a 2004 image taken by the Mars Exploration Rover Spirit.A rock outcrop dubbed Longhorn and the sweeping plains of the Gusev crater are seen in a 2004 image taken by the Mars Exploration Rover Spirit.
Although it is 45 kilometers (28 miles) wide, countless layers of ice and dust have all but buried the Udzha crater on Mars. The crater lies near the edge of the northern polar cap. This image was taken by NASA's Mars Odyssey Orbiter in 2010.Although it is 45 kilometers (28 miles) wide, countless layers of ice and dust have all but buried the Udzha crater on Mars. The crater lies near the edge of the northern polar cap. This image was taken by NASA's Mars Odyssey Orbiter in 2010.
NASA's Opportunity examines rocks inside an alcove called Duck Bay in the western portion of the Victoria crater in 2007.NASA's Opportunity examines rocks inside an alcove called Duck Bay in the western portion of the Victoria crater in 2007.
Pictured is a series of troughs and layered mesas in the Gorgonum Chaos region of Mars in 2008. This photo was taken by Mars Orbiter Camera on the Mars Global Surveyor.Pictured is a series of troughs and layered mesas in the Gorgonum Chaos region of Mars in 2008. This photo was taken by Mars Orbiter Camera on the Mars Global Surveyor.
An image captured in 2008 by NASA's Mars Reconnaissance Orbiter shows at least four Martian avalanches, or debris falls, taking place. Material, likely including fine-grained ice and dust and possibly large blocks, detached from a towering cliff and cascaded to the gentler slopes below.An image captured in 2008 by NASA's Mars Reconnaissance Orbiter shows at least four Martian avalanches, or debris falls, taking place. Material, likely including fine-grained ice and dust and possibly large blocks, detached from a towering cliff and cascaded to the gentler slopes below.
This 2008 image spans the floor of Ius Chasma's southern trench in the western region of Valles Marineris, the solar system's largest canyon. Ius Chasma is believed to have been shaped by a process called sapping -- in which water seeped from the layers of the cliffs and evaporated before it reached the canyon floor. This 2008 image spans the floor of Ius Chasma's southern trench in the western region of Valles Marineris, the solar system's largest canyon. Ius Chasma is believed to have been shaped by a process called sapping -- in which water seeped from the layers of the cliffs and evaporated before it reached the canyon floor.
Pictured is the Martian landscape at Meridiani Planum, where the Mars Exploration Rover Opportunity successfully landed in 2004. This is one of the first images beamed back to Earth from the rover shortly after it touched down.Pictured is the Martian landscape at Meridiani Planum, where the Mars Exploration Rover Opportunity successfully landed in 2004. This is one of the first images beamed back to Earth from the rover shortly after it touched down.
An image from the Mars Global Surveyor in 2000 shows potential evidence of massive sedimentary deposits in the western Arabia Terra impact crater on the surface of Mars.An image from the Mars Global Surveyor in 2000 shows potential evidence of massive sedimentary deposits in the western Arabia Terra impact crater on the surface of Mars.
The Mars Reconnaissance Orbiter captures a dust devil blowing across the Martian surface east of the Hellas impact basin in 2007. Dust devils form when the temperature of the atmosphere near the ground is much warmer than that above. The diameter of this dust devil is about 200 meters (650 feet).The Mars Reconnaissance Orbiter captures a dust devil blowing across the Martian surface east of the Hellas impact basin in 2007. Dust devils form when the temperature of the atmosphere near the ground is much warmer than that above. The diameter of this dust devil is about 200 meters (650 feet).
Soft soil is exposed when the wheels of NASA's Mars Exploration Rover Spirit dig into a patch of ground dubbed Troy in 2009.Soft soil is exposed when the wheels of NASA's Mars Exploration Rover Spirit dig into a patch of ground dubbed Troy in 2009.
An image from NASA's Mars Reconnaissance Orbiter shows the floor of the Antoniadi Crater in 2009.An image from NASA's Mars Reconnaissance Orbiter shows the floor of the Antoniadi Crater in 2009.
The larger of Mars' two moons, Phobos, is seen in 2008 from the Mars Reconnaissance Orbiter.The larger of Mars' two moons, Phobos, is seen in 2008 from the Mars Reconnaissance Orbiter.
Earth and the moon are seen in 2007 from the Mars Reconnaissance Orbiter. At the time the image was taken, Earth was 142 million kilometers (88 million miles) from Mars.Earth and the moon are seen in 2007 from the Mars Reconnaissance Orbiter. At the time the image was taken, Earth was 142 million kilometers (88 million miles) from Mars.
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Photos: Exploring MarsPhotos: Exploring Mars
Rover on a mission to Mars
NASA's search for signs of life on Mars
The Number: "Curiosity" Mars landing

Even after all these years, "You still see a lot of excitement" at Opportunity's control center at JPL," Tompkins said.

NASA spent $800 million to launch Opportunity and its sister rover, Spirit. The twin craft lifted off from Cape Canaveral in June 2003 aboard separate Delta II rockets and landed successfully the following January, bouncing onto the surface inside a cocoon of air bags.

The roughly 5-foot-long, 380-pound rovers were loaded with a variety of cameras and instruments used to analyze martian rocks and soil, and their findings have helped convince NASA that Mars once had water on its surface.

'Crazy' Mars landing coming

NASA lost contact with Spirit in 2010 and wrote off the rover in May 2011, but Opportunity kept on going. Among its findings was a vein of the mineral gypsum -- an indication that water once ran across the surface of the Red Planet. And it beamed back its 100,000th picture, a sweeping panorama of the martian surface, in early July.

Not that it's been unscathed. It's got a worn "shoulder" joint on its robotic arm, making some operations difficult. It was stuck in a sand dune for nearly two months in mid-2005. But it has had unexpected luck, as well.

"The solar panels were expected to collect a lot of dust, and they did," Tompkins said. "But we've had winds that have cleaned the solar panels occasionally, and that has given it a new lease on life."

Tompkins is now working on the much-larger Curiosity. Designers built the 2,000-pound craft with lessons from Spirit and Opportunity in mind, including a longer, more advanced robot arm, a hammer drill that can crack apart rocks and a laser that reduces rock to a hot plasma, allowing an on-board spectrograph to determine its composition.

Opportunity's neighborhood is known as the Meridiani Planum, a sandy desert located a few degrees south and west of the martian equator and its prime meridian. The site is nearly halfway around the planet from Spirit's location, and from where Curiosity is expected to touch down at 1:31 a.m. Monday ET.

It can run more than 100 meters (325 feet) in a day, but it's not exactly a speed demon: Opportunity tops out at about 2 inches a second. But it's also capable of climbing up to 30-degree slopes.

Building an out-of-this-world menu for Mars

Tompkins says the goal for operators is "pushing the limits and keeping it safe."

"The fact that the rovers have lasted also has to do with how carefully you operate them," she said.

The average distance between the Earth and Mars is about 225 million miles, but it varies widely during the year as both planets orbit the sun. When they're the farthest apart -- about 400 million miles -- a radio signal from NASA takes more than half an hour to reach the rovers.

That means controllers have to pre-program Opportunity's daily movements, working from a three-dimensional model of the surrounding terrain, Tompkins said. JPL transmits the plan to the rover, which carries out the program and beams the data back to Earth via two satellites now circling the Red Planet, the Mars Odyssey and Mars Reconnaissance Orbiter. That means the programs have to be completed by the time those satellites are in range, adding one more wrinkle to controllers' calculations.

"Imagine planning your drive from your home to your office," she said. "Even though you know that route truly well and there's no traffic, imagine having to pre-think all those options. Then imagine it's raining."

Complete coverage on the Mars landing

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