Curiosity Makes Its Longest One-Day Drive on Mars

PASADENA, Calif. – NASA's Mars rover Curiosity drove twice as far on July 21 as on any other day of the mission so far: 109.7 yards (100.3 meters). The length of the drive took advantage of starting the 340th Martian day, or sol, of the mission from a location with an unusually good view for rover engineers to plan a safe path. In weeks to come, the rover team plans to begin using "autonav" capability for the rover to autonomously navigate a path for itself, which could make such long drives more frequent.

Curiosity is about three weeks into a multi-month trek, from the "Glenelg" area where it worked for the first half of 2013, to an entry point for the mission's major destination: the lower layers of Mount Sharp. The mission's longest one-day drive prior to July 21 was about 54 yards (49 meters), on Sol 50 (Sept. 26, 2012). After completing the longer drive, Curiosity drove 68.2 yards (62.4 meters) on July 23 (Sol 342), bringing the mission's total driving distance so far to 0.81 mile (1.23 kilometers).

The Sol 340 drive included three segments, with turns at the end of the first and second segments. Rover planners used information from stereo imaging by the Navigation Camera (Navcam) on Curiosity's mast, plus images from the telephoto-lens Mast Camera (Mastcam).  The drive also used the rover's capability to use imagery taken during the drive to calculate the driving distance, a way to verify that wheels have not been slipping too much while turning.

"What enabled us to drive so far on Sol 340 was starting at a high point and also having Mastcam images giving us the size of rocks so we could be sure they were not hazards," said rover planner Paolo Bellutta of NASA's Jet Propulsion Laboratory, Pasadena, Calif. “We could see for quite a distance, but there was an area straight ahead that was not clearly visible, so we had to find a path around that area."

The rover was facing southwest when the sol began. It turned slightly more to the west before driving and used visual odometry to be sure it drove the intended distance (about 55 yards or 50 meters) before turning back farther southward. The second leg, next turn, and third leg completed the drive without visual odometry, though the rover was using another new capability: to turn on visual odometry autonomously if tilt or other factors exceed predetermined limits. New software on Curiosity gives it the capability to use visual odometry through a range of temperatures. This was needed because testing this spring indicated the Navcam pair linked to the rover's B-side computer is more sensitive to temperature than anticipated. Without the compensating software, the onboard analysis of stereo images could indicate different distances to the same point, depending on the temperature at which the images are taken. The rover was switched from its A-side computer to the redundant B-side computer on Feb. 28 due to a flash-memory problem -- subsequently resolved -- on the A-side. The Navcam pair linked to the A-side computer shows less variability with temperature than the pair now in use.

"For now, we're using visual odometry mostly for slip-checking," said JPL's Jennifer Trosper, deputy project manager for Curiosity. "We are validating the capability to begin using autonav at different temperatures." The autonomous navigation capability will enable rover planners to command drives that go beyond the route that they can confirm as safe from previous-sol images. They can tell the rover to use the autonomous capability to choose a safe path for itself beyond that distance.

Curiosity landed at the "Bradbury Landing" location within Gale Crater on Aug. 6, 2012, EDT and Universal Time (Aug. 5, PDT). From there, the rover drove eastward to the Glenelg area, where it accomplished the mission's major science objective of finding evidence for an ancient wet environment that had conditions favorable for microbial life. The rover's route is now southwestward. At Mount Sharp, in the middle of Gale Crater, scientists anticipate finding evidence about how the ancient Martian environment changed and evolved.

JPL, a division of the California Institute of Technology, Pasadena, manages the Mars Science Laboratory Project for NASA's Science Mission Directorate, Washington. JPL designed and built the project's Curiosity rover. More information about Curiosity is online at http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl/ . You can follow the mission on Facebook at http://www.facebook.com/marscuriosity and on Twitter at http://www.twitter.com/marscuriosity .

Source: http://www.nasa.gov

Mars rover Opportunity examining rock changed by water

The mission's engineers at NASA's Jet Propulsion Laboratory, Pasadena, California, 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," Scott McLennan of the State University of New York, Stony Brook, a long-term planner for Opportunity's science team, said.

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 Endeavor Crater, which spans 14 miles (22 kilometers) across. The planned driving route to Solander Point is about 1.4 miles (2.2 kilometers). 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 had detected a clay mineral. (ANI)

NASA Wallops rolls out the Antares for next week's test launch

WALLOPS ISLAND — The fully integrated Antares rocket was rolled out over the weekend to prepare for next week's long-awaited launch from the Mid-Atlantic Regional Spaceport (MARS) at NASA Wallops Flight Facility on the Eastern Shore. A 135-foot, medium-lift rocket, the Antares will be the largest ever to launch out of Wallops since the flight facility was established in 1945. The launch is set for 5 p.m. Wednesday, April 17, but NASA officials say the larger launch window is 5 to 8 p.m. that day through April 21.

The Antares and its Cygnus cargo spacecraft were developed and built by Orbital Sciences Corporation, a space transportation company based in Dulles, as part of its $1.9 billion contract with NASA to resupply the International Space Station through 2016. According to Orbital, the Antares is capable of lifting about 11,000 pounds of payload such as crew supplies and scientific experiments into low-earth orbit. "In layman's terms, a small-lift is a pickup truck, medium-lift is a semi and heavy-lift would be a train," said Dale K. Nash, executive director of the Virginia Commercial Space Flight Authority that oversees MARS. "That's a fairly significant step into that market," Nash said, "and resupplying the International Space Station is a very critical, very challenging mission."

According to Wallops Flight Facility spokesman Keith Koehler, about 100 media representatives, including social media and three international new organizations, have been credentialed so far to view the launch from Wallops. If it's successful, a mission later this year will launch the Cygnus to demonstrate it can rendezvous with the space station. If that succeeds, Orbital will conduct eight resupply missions out of MARS. State leaders hope having Orbital as a key customer will establish its spaceport as a major hub for the emerging commercial space industry, attract other commercial customers and bring investment and jobs to the state and region.

Orbital has said Antares launches will be visible throughout Hampton Roads, but the NASA Wallops website indicates two primary viewing locations for launches. One is at the Wallops Visitors Center along Virginia Highway 175, and the other is the beach on the Virginia side of Assateague Island, although capacity is based on such factors as the time of year and the state of the beach.