Today, NASA
is offering a chance to go one-on-one with the team of engineers who are
working to free the stuck Mars rover Spirit.
So if
you've got an idea for how to liberate the
Martian rover from its sandy trap on the red planet — or have a question
for how the engineers are working on ways to get the rover out — today's NASA webcast
is the time to ask. Call it Operation: Free Spirit.
Spirit has
been stuck
in Martian dirt up to its hubcaps since May 6, when it became mired in a
dirt patch (now called "Troy") while driving backward.
Because
they don't want to damage Spirit while trying out ways to get the rover out of
its sand trap, mission engineers are using a replica model here on Earth.
Two members
of the engineering team — John Callas, project manager for NASA's Mars
Exploration Rovers, and Ashley Stroupe, deputy lead for "Free Spirit"
testing — will talk about their efforts in a live webcast from NASA's Jet
Propulsion Laboratory in Pasadena, Calif. at 6 p.m. EDT at the following web
address: http://www.ustream.tv/channel/nasajpl
Questions
can be submitted via Ustream or Twitter (to @NASAJPL using the hashtag
#FreeSpirit) during the webcast and in advance to chatquestion@jpl.nasa.gov.
The team
has already received suggestions from fans of the hard luck rover, including
using the robotic arm to hoist the robot out of the sand. But the arm doesn't
have enough force to lift the hefty rover, Callas said.
"The
rover's far too massive, far too heavy," Callas said. Spirit and its
robotic twin Opportunity are each the size of a golf cart.
Other
suggestions have included using the robotic arm to push sand away from the
wheels, or underneath them for better traction. "And that's an interesting
idea," Callas said, but would have to be looked at much later in the
testing process.
At the end
of June, the test rover was set up in a plywood rig in a dirt pit at JPL. The
rig is filled with a dirt concoction mixed to mimic the properties of the sand
in which Spirit is stuck. It is also tilted at a 10-degree angle - the same
angle of the slope that Spirit is stuck on.
Engineers
also placed a rock underneath the test rover's belly because images taken last
month by the microscopic imager at the end of Spirit's robotic arm. After
analyzing the image, mission managers determined that a dark blob in the middle
was a rock positioned underneath the rover.
Mission
engineers finally began testing out possible maneuvers on July 6. So far, they
have 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're
looking at all the kinds of motion we can try," Callas said.
Some of
these tests will be played during the live webcast.
Mission
operators have found evidence that the dirt in which Spirit is stuck isn't
uniform: the sand on the right side of the rover seems to be more compacted and
have better traction than that on the right," so we want to try and
exploit that," Callas told SPACE.com.
To better
simulate Spirit's situation, the engineers plan to take out the mock Mars sand under
the right side of the test rover and replace it with dirt that has properties
closer to the stuff under Spirit.
After the
team has run through their series of test moves with the new dirt mixture, they
hope they'll have an idea of what maneuver might work best.
"We
want to try the very best thing the first time," Callas said. "Our
first chance will be our best chance" to get the rover free.
"We do
want to start trying things on Mars fairly soon," Callas said. But since
the rover has plenty of juice and is doing science in its current spot, the
team isn't in any hurry.
"We
have time on our hands," Callas said.
To watch
NASA's Mars rover webcast at 6 p.m. EDT today, visit here: http://www.ustream.tv/channel/nasajpl
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