Got an Idea to Save Spirit? Mars Rover Engineers Are All Ears

Got an Idea to Save Spirit? Mars Rover Engineers Are All Ears
Mars Exploration Rover team members on July 21, 2009, tested how altering the order in which individual wheels turn for steering affects how those turns dig the wheels deeper into soft soil. From left: Alfonso Herrera, Vandana Verma, Bruce Banerdt.
(Image: © NASA/JPL-Caltech)

Today, NASAis offering a chance to go one-on-one with the team of engineers who areworking to free the stuck Mars rover Spirit.

So ifyou've got an idea for how to liberate theMartian rover from its sandy trap on the red planet ? or have a questionfor how the engineers are working on ways to get the rover out ? today?s NASA webcastis the time to ask. Call it Operation: Free Spirit.

Spirit hasbeen stuckin Martian dirt up to its hubcaps since May 6, when it became mired in adirt patch (now called "Troy") while driving backward.

Becausethey don't want to damage Spirit while trying out ways to get the rover out ofits sand trap, mission engineers are using a replica model here on Earth.

Two membersof the engineering team ? John Callas, project manager for NASA's MarsExploration Rovers, and Ashley Stroupe, deputy lead for "Free Spirit"testing ? will talk about their efforts in a live webcast from NASA's JetPropulsion Laboratory in Pasadena, Calif. at 6 p.m. EDT at the following webaddress: http://www.ustream.tv/channel/nasajpl

Questionscan be submitted via Ustream or Twitter (to @NASAJPL using the hashtag#FreeSpirit) during the webcast and in advance to chatquestion@jpl.nasa.gov.

The teamhas already received suggestions from fans of the hard luck rover, includingusing the robotic arm to hoist the robot out of the sand. But the arm doesn'thave enough force to lift the hefty rover, Callas said.

"Therover's far too massive, far too heavy," Callas said. Spirit and itsrobotic twin Opportunity are each the size of a golf cart.

Othersuggestions have included using the robotic arm to push sand away from thewheels, or underneath them for better traction. "And that's an interestingidea," Callas said, but would have to be looked at much later in thetesting process.

At the endof June, the test rover was set up in a plywood rig in a dirt pit at JPL. Therig is filled with a dirt concoction mixed to mimic the properties of the sandin which Spirit is stuck. It is also tilted at a 10-degree angle - the sameangle of the slope that Spirit is stuck on.

Engineersalso placed a rock underneath the test rover's belly because images taken lastmonth by the microscopic imager at the end of Spirit's robotic arm. Afteranalyzing the image, mission managers determined that a dark blob in the middlewas a rock positioned underneath the rover.

Missionengineers finally began testing out possible maneuvers on July 6. So far, theyhave tried out driving forward, backward, and then a series of crab-like moves.They have also tried out pivoting around the rover's bum right-front wheel,which has been inoperable for three years.

"We'relooking at all the kinds of motion we can try," Callas said.

Some ofthese tests will be played during the live webcast.

Missionoperators have found evidence that the dirt in which Spirit is stuck isn'tuniform: the sand on the right side of the rover seems to be more compacted andhave better traction than that on the right," so we want to try andexploit that," Callas told SPACE.com.

To bettersimulate Spirit's situation, the engineers plan to take out the mock Mars sand underthe right side of the test rover and replace it with dirt that has propertiescloser to the stuff under Spirit.

After theteam has run through their series of test moves with the new dirt mixture, theyhope they'll have an idea of what maneuver might work best.

"Wewant to try the very best thing the first time," Callas said. "Ourfirst chance will be our best chance" to get the rover free.

"We dowant to start trying things on Mars fairly soon," Callas said. But sincethe rover has plenty of juice and is doing science in its current spot, theteam isn't in any hurry.

"Wehave time on our hands," Callas said.

  • SPACE.com Video Show - Rover Tracks on Mars
  • Video - Spirit: The Little Rover That Could
  • The Most Amazing Mars Rover Discoveries

 

To watchNASA?s Mars rover webcast at 6 p.m. EDT today, visit here: http://www.ustream.tv/channel/nasajpl

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