NASA Curiosity Rover: Long-lived rover sets off-world driving record

This natural colour view from NASA's Mars Exploration Rover Opportunity shows "Lunokhod Crater," which lies south of Solander Point on the west rim of Endeavour Crater. 

Credit: NASA/JPL-Caltech /Cornell /Arizona State Univ.

NASA's Opportunity Mars rover, which landed on the Red Planet in 2004, now holds the off-Earth roving distance record after accruing 25 miles (40 kilometers) of driving.

The previous record was held by the Soviet Union's Lunokhod 2 rover.

"Opportunity has driven farther than any other wheeled vehicle on another world," said Mars Exploration Rover Project Manager John Callas, of NASA's Jet Propulsion Laboratory in Pasadena, California.

"This is so remarkable considering Opportunity was intended to drive about one kilometer and was never designed for distance but what is really important is not how many miles the rover has racked up, but how much exploration and discovery we have accomplished over that distance."

A drive of 157 feet (48 meters) on July 27 put Opportunity's total odometry at 25.01 miles (40.25 kilometers).

This month's driving brought the rover southward along the western rim of Endeavour Crater.

The rover had driven more than 20 miles (32 kilometers) before arriving at Endeavour Crater in 2011, where it has examined outcrops on the crater's rim containing clay and sulfate-bearing minerals.

The sites are yielding evidence of ancient environments with less acidic water than those examined at Opportunity's landing site.

If the rover can continue to operate the distance of a marathon, 26.2 miles (about 42.2 kilometers), it will approach the next major investigation site mission scientists have dubbed "Marathon Valley."

Observations from spacecraft orbiting Mars suggest several clay minerals are exposed close together at this valley site, surrounded by steep slopes where the relationships among different layers may be evident.

The Russian Lunokhod 2 rover, a successor to the first Lunokhod mission in 1970, landed on Earth's moon on Jan. 15, 1973, where it drove about 24.2 miles (39 kilometers) in less than five months, according to calculations recently made using images from NASA's Lunar Reconnaissance Orbiter (LRO) cameras that reveal Lunokhod 2's tracks.

Irina Karachevtseva at Moscow State University of Geodesy and Cartography's Extraterrestrial Laboratory in Russia, Brad Jolliff of Washington University in St. Louis, Tim Parker of JPL, and others collaborated to verify the map-based methods for computing distances are comparable for Lunokhod-2 and Opportunity.

This chart illustrates comparisons among the distances driven by various wheeled vehicles on the surface of Earth's moon and Mars. 

Of the vehicles shown, the NASA Mars rovers Opportunity and Curiosity are still active and the totals for those two are distances driven as of May 15, 2013.

Credit: NASA/JPL-Caltech

"The Lunokhod missions still stand as two signature accomplishments of what I think of as the first golden age of planetary exploration, the 1960s and '70s," said Steve Squyres of Cornell University in Ithaca, New York, and principal investigator for NASA's twin Mars rovers, Opportunity and Spirit.

"We're in a second golden age now, and what we've tried to do on Mars with Spirit and Opportunity has been very much inspired by the accomplishments of the Lunokhod team on the moon so many years ago. It has been a real honour to follow in their historical wheel tracks."

As Opportunity neared the mileage record earlier this year, the rover team chose the name Lunokhod 2 for a crater about 20 feet (6 meters) in diameter on the outer slope of Endeavour's rim on Mars.

Mars Curiosity Rover: MERS Robotic Arm Crushes Sledge Island for MSL Study

Opportunity is exploring 'Murray Ridge' on Solander Point, part of the rim of Endeavour Crater.

Investigation continued on 'Anchor Point,' Sol 3581 (Feb. 19, 2014) through Sol 3583 (Feb. 21, 2014), with Microscopic Imager (MI) and Alpha Particle X-ray Spectrometer (APXS) on two soil locations.

On Sol 3585 (Feb. 23, 2014), the arm crushed the rock 'Sledge Island' some more and then backed up to inspect the results.

Sledge Island was indeed crushed, and parts of it were in the Instrument Deployment Device (IDD) work volume.

The team generated a Microscopic Imager (MI) mosaic and placed the APXS on it Sol 3587 (Feb. 25, 2014).

The subsequent integration appears to have been successful. This should largely wrap-up the work at the current location, though the team will attempt to crack 'Stuart Island' under the wheel as the rover drives away.

As of Sol 3588 (Feb. 26, 2014), the solar array energy production was 464 watt-hours with an atmospheric opacity (Tau) of 0.498 and a solar array dust factor of 0.691.

Total odometry is 24.07 miles (38.74 kilometers).

NASA Mars Rover Opportunity examines clay clues in rock Esperance

The pale rock in the upper center of this image, about the size of a human forearm, includes a target called "Esperance," which was inspected by NASA's Mars Exploration Rover Opportunity.

Data from the rover's Alpha Particle X-ray Spectrometer (APXS) indicate that Esperance's composition is higher in aluminum and silica, and lower in calcium and iron, than other rocks Opportunity has examined in more than nine years on Mars.

Preliminary interpretation points to clay mineral content due to intensive alteration by water. 

Image Credit: NASA/JPL-Caltech/Cornell/Arizona State Univ.

NASA's senior Mars rover, Opportunity, is driving to a new study area after a dramatic finish to 20 months on "Cape York" with examination of a rock intensely altered by water.

The fractured rock, called "Esperance," provides evidence about a wet ancient environment possibly favorable for life.

Steve Squyres

The mission's principal investigator, Steve Squyres of Cornell University, Ithaca, N.Y., said, "Esperance was so important, we committed several weeks to getting this one measurement of it, even though we knew the clock was ticking."

The mission's engineers at NASA's Jet Propulsion Laboratory, Pasadena, Calif., had set this week as a deadline for starting a drive toward "Solander Point," where the team plans to keep Opportunity working during its next Martian winter.

"What's so special about Esperance is that there was enough water not only for reactions that produced clay minerals, but also enough to flush out ions set loose by those reactions, so that Opportunity can clearly see the alteration," said Scott McLennan of the State University of New York, Stony Brook, a long-term planner for Opportunity's science team.

This map of a portion of the western rim of Endeavour Crater on Mars shows the area where NASA's Mars Exploration Rover Opportunity worked for 20 months, "Cape York," in relation to the area where the rover team plans for Opportunity to spend its sixth Martian winter, "Solander Point."

This rock's composition is unlike any other Opportunity has investigated during nine years on Mars—higher in aluminum and silica, lower in calcium and iron.

The next destination, Solander Point, and the area Opportunity is leaving, Cape York, both are segments of the rim of Endeavour Crater, which spans 14 miles (22 kilometers) across.

The planned driving route to Solander Point is about 1.4 miles (2.2 kilometers).

Cape York has been Opportunity's home since the rover arrived at the western edge of Endeavour in mid-2011 after a two-year trek from a smaller crater.

"Based on our current solar-array dust models, we intend to reach an area of 15 degrees northerly tilt before Opportunity's sixth Martian winter," said JPL's Scott Lever, mission manager.

Scott McLennan

"Solander Point gives us that tilt and may allow us to move around quite a bit for winter science observations."

Northerly tilt increases output from the rover's solar panels during southern-hemisphere winter.

Daily sunshine for Opportunity will reach winter minimum in February 2014. The rover needs to be on a favourable slope well before then.

This mosaic of four frames shot by the microscopic imager on the robotic arm of NASA's Mars Exploration Rover Opportunity shows a rock target called "Esperance" after some of the rock's surface had been removed by Opportunity's rock abrasion tool, or RAT. 

Credit: NASA/JPL-Caltech /Cornell /USGS

The first drive away from Esperance covered 81.7 feet (24.9 meters) on May 14.

Three days earlier, Opportunity finished exposing a patch of the rock's interior with the rock abrasion tool.

The team used a camera and spectrometer on the robotic arm to examine Esperance.

JPL's Scott Lever, mission manager

The team identified Esperance while exploring a portion of Cape York where the Compact Reconnaissance Spectrometer for Mars (CRISM) on NASA's Mars Reconnaissance Orbiter (MRO) had detected a clay mineral.

Clays typically form in wet environments that are not harshly acidic.

For years, Opportunity had been finding evidence for ancient wet environments that were very acidic.

The CRISM findings prompted the rover team to investigate the area where clay had been detected from orbit.

There, they found an outcrop called "Whitewater Lake," containing a small amount of clay from alteration by exposure to water.

"There appears to have been extensive, but weak, alteration of Whitewater Lake, but intense alteration of Esperance along fractures that provided conduits for fluid flow," Squyres said.

"Water that moved through fractures during this rock's history would have provided more favourable conditions for biology than any other wet environment recorded in rocks Opportunity has seen."