Curiosity Rover Completes Autonomous Two-Day Drive, Approaches 'Cooperstown'

Brett Smith for redOrbit.com – Your Universe Online

The Mars Curiosity rover finished its first two-day autonomous roll across the Martian landscape on Monday, bringing the roving laboratory to an ideal vantage point for selecting a next target to investigate, NASA announced on Tuesday.

When Curiosity drives autonomously, it chooses a route by using its onboard computer to analyze stereo pictures that it takes during stops. Before Monday, each day’s drive came after a section earlier in the day that was charted by NASA using images sent to Earth. The two-day drive, which began on Sunday, was the first time Curiosity ended one autonomous segment and continued another from the following day.

The two-day road trip took Curiosity to just over 260 feet from ‘Cooperstown,’ a targeted rocky outcropping that NASA plans to examine using the rover’s onboard instruments. Curiosity last used its sampling instruments when it visited an outcrop called ‘Darwin’ on September 22. Researchers used the rover’s arm camera and an onboard spectrometer for four days at Darwin; they plan to use them for just a single day at Cooperstown.

The shift to two-day autonomous driving and the shorter examining sessions are part of the plan to accelerate Curiosity’s trip toward the mission’s main target: Mount Sharp.

In July, Curiosity began a 5.3-mile drive, starting from the Yellowknife Bay area where it worked for the first half of 2013. Cooperstown is about one-third of the way from the destination of Mount Sharp. The NASA scientists used images from NASA’s Mars Reconnaissance Orbiter to plan the route and select a few stops along the way, such as Darwin and Cooperstown.

“What interests us about this site is an intriguing outcrop of layered material visible in the orbital images,” said Kevin Lewis, a geoscientist from Princeton University who has been a leader in planning the Cooperstown activities. “We want to see how the local layered outcrop at Cooperstown may help us relate the geology of Yellowknife Bay to the geology of Mount Sharp.”

The two-day trip began Sunday, driving about 180 feet on a southwestward path that rover drivers had evaluated ahead of time as safe. The autonomous-driving began where that initial roll left off, with Curiosity determining the ideal way to reach designated points ahead, driving about 125 feet on Sunday.

“We needed to store some key variables in the rover’s non-volatile memory for the next day,” said remote rover driver John Wright. Curiosity’s volatile memory is wiped clean when the rover goes into sleep mode overnight.

The stored data included what direction the rover was driving when it stopped, and whether the next 10 feet in that direction had been classified as safe for driving. The next day, Curiosity resumed scanning the terrain ahead for safe driving and autonomously drove another 105 feet.

Successful completion of the two-day drive means NASA can schedule extra driving days during multi-day itineraries that the rover team draws up on Fridays and before holidays.

NASA said it plans to upload a new version of onboard software next week, which would be the third such upgrade since landing. The software upgrades allow for additional advancement in the rover’s capabilities. For example, the next update improves what information the rover can retain overnight to resume autonomous driving the next day. It also expands the use of the robotic arm while parked on slopes.