Spirit Rover: Rear Wheel Trouble Continues

Dec 10, 2009
An artist's concept portrays a NASA Mars Exploration Rover on the surface of Mars. Image credit: NASA/JPL/Cornell University

(PhysOrg.com) -- Results of diagnostic tests on Spirit's right-rear wheel on Sol 2109 (Dec. 8, 2009) continue to indicate a troubled wheel, which may leave the rover with only four operable wheels.

The Sol 2109 plan included a check of the grind motor of Spirit's rock abrasion tool (RAT) because it shares the same motor controller as the right-rear wheel. It also included rotor resistance tests on the right-rear motor at three temperatures using opposite voltage polarity from earlier tests, backward and forward commanded motion of the right-rear wheel, and a check of rotor resistance on all other operating wheels. The RAT motor appears okay, although a more exhaustive test will be tried later.

The right-rear wheel rotor resistance tests continue to show very elevated resistance, although not as high as in previous tests, and exhibiting a curious voltage-dependent effect. No motion of the right-rear wheel occurred during the backward commanded motion. The forward motion was not executed since the initial backward motion did not occur. The rotor resistances on all the other operating wheels are nominal.

The plan ahead, still being developed, will likely include more resistance tests, an attempt to apply higher voltage to the right-rear wheel to see if any movement will occur, and a check of the right-front wheel to confirm its status and to see if it may offer insight into the right-rear wheel's condition. Further ahead, steering tests will be considered to explore an external jam as a possible explanation.

Concurrent with this, the project is exploring whether any meaningful rover motion would be possible with only four operable wheels. Spirit lost the use of its right front in 2006.

Because of the current rover tilt, the environmental conditions and accumulation on the , Spirit is at risk of inadequate power for surviving through the next southern Mars winter, which reaches solstice on May 13, 2009. Even if extrication is not possible, some limited rover motion may be able to improve rover tilt and increase the chance of winter survival.

Provided by JPL/NASA (news : web)

Explore further: Liquid crystal bubble OASIS in space

Related Stories

Further Tests Designed for Rover's Right-Rear Wheel

Dec 08, 2009

(PhysOrg.com) -- A series of diagnostic tests on Spirit's right-rear wheel on sols 2104 and 2105 (Dec. 3 and 4) investigated stalls that occurred on Sol 2099 (Nov. 28) and earlier. The rover team cannot draw ...

NASA Investigates Problems With Spirit

Oct 06, 2004

Engineers on NASA's Mars Exploration Rover team are investigating possible causes and remedies for a problem affecting the steering on Spirit. The relay for steering actuators on Spirit's right-front and lef ...

Spirit Completes Fourth Mile On Mars

Feb 14, 2006

Spirit is healthy and continues to make progress toward "Home Plate" after driving more than 150 meters (492 feet), taking images, making atmospheric observations, and analyzing geology.

Recommended for you

Liquid crystal bubble OASIS in space

8 hours ago

No matter how beautiful or crystal clear the bubbling waters of an oasis may be, they seldom lead to technology breakthroughs. Yet, NASA's OASIS investigation's bubbles may lead to an ocean of new improvements ...

Zapping away space junk

17 hours ago

Planet Earth is surrounded. Thousands of tons of dangerous space debris circle in low orbit, threatening serious damage, even death, if any were to strike the International Space Station. A proposal by a ...

Ariane 5's first launch of 2015

19 hours ago

An Ariane 5 has lifted off from Europe's Spaceport in Kourou, French Guiana and delivered two telecom satellites into their planned orbits.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.