Wheel Woes For Mars Rover
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PASADENA, Calif.   The Mars rover Spirit has developed a problem with one of its six wheels, but NASA officials said Tuesday they believe the robot geologist can continue working.
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The Mars Exploration Rovers, Spirit and Opportunity, will claim a place in history as tremendous successes. But to get the rovers ready for launch, mission team members had to push themselves to their limits. MER Principal Investigator Steve Squyres explains how they handled the challenge.
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London - An unexplained phenomenon akin to a space-borne carwash has boosted the performance of one of the two US rovers probing the surface of Mars, New Scientist magazine said on Tuesday.
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Engineers test an airbag system that could be used to cushion a European rover's landing on Mars.
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The twin Mars rovers have found a wonderland of weird rocks and enticing dunes along with more evidence the Red Planet once had water, NASA scientists said Wednesday.
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After three years on Mars, NASA rovers built for a three-month mission face their toughest foe: Martian sandstorms blocking the sunlight that charges their batteries.
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Even though they were expected to explore the Mars surface for only 90 days, the two Mars rovers are still gathering information about the Red Planet. This week, NASA extended their missions again.
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When the Mars rovers Opportunity and Spirit reached their distant destination in early 2004, NASA scientists hoped the vehicles would probe the planet's frigid landscape for 90 days before they pooped out or were undone by the harsh Martian environment.
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NASA's&nbsp;twin&nbsp;Mars rovers&nbsp;Spirit and Opportunity&nbsp;have  yielded volumes of new data about the red planet in the last year - the least of  which involves the planet's history of water. But the rovers have also amazed  their human handlers with their longevity, lasting nearly four times&nbsp;their  initial 90-day mission&nbsp;despite some early glitches that popped up after  landing.
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Checking out the rocks The Mars Rover Opportunity has started its exploration of the Victoria crater. The images it is sending back suggest any previous (or current, but hidden) inhabitants of the red planet had a bit of a thing for crazy paving.â¦
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Jet Propulsion Lab -- 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 left-rear wheels did not operate as commanded on Oct...
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After an arduous 21-month journey, the Mars rover Opportunity edged close enough to the rim of a large crater yesterday to send back its first photos of the bottom and rocky sides of the dramatic site. What they showed left researchers increasingly confident that their robotic explorer had reached...
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One of the Mars rovers that have spent most of the past year studying the ruddy rocks and soil on the Red Planet is now taking a close look at some of the junk it shed during its fiery descent last January.
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Ten months after NASA&#39;s twin rovers landed on Mars, scientists reported this week that both robotic vehicles are still navigating their rock-studded landscapes with all instruments operating
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Extreme PlanetThough both rovers are exploring Mars well beyond their initial 90-day missions, electrical connections and moving parts are showing signs of temperature-related fatigue.&quot;Every day we have a huge thermal cycle,&quot; notes Jake Matijevic, chief of the rover engineering team. &quot;That causes the solder in electrical connections to expand and contract until it breaks.&quot;Seasonal ChangeDuring their exploration of Mars, the rovers have recorded temperatures ranging from midday highs of about 35 degrees C. (95 degrees F.) in spring and summer to nighttime lows of about minus 110 degrees C. (minus 166 degrees F.) in winter. Spirit has experienced greater swings in temperature because its location is farther from the martian equator, which puts it seasonally closer to or farther from the Sun than Opportunity.Three Years of DataRover engineer Dan Porter has been tracking temperatures recorded by 50 or so sensors on each of the rovers since shortly after they landed on Mars in January 2004. The results are not only of interest to scientists, they're a favorite of human audiences as well.&quot;People ask about this all the time,&quot; says New Mexico geologist Larry Crumpler, a member of the Mars rover science team who created the charts showing monthly average temperatures superimposed on panoramic-camera images from each of the rovers. &quot;These plots of daily temperature are destined to become an important part of all my public outreach talks.&quot;Cold vs. ColderJust as on Earth, temperatures on Mars are not uniform everywhere. Objects exposed to direct sunlight are apt to be warmer than those in the shade. Some objects retain heat better than others. A source of relative warmth on Mars is rocky terrain, because it retains heat better than sandy terrain.A solar panel is sort of like a &quot;warm wall in mid-winter,&quot; says Crumpler. Components beneath the solar panels, such as the hazard avoidance cameras, are closer in temperature to the martian air. Unlike Earth, Mars does not have a thick, atmospheric blanket to seal in warmth by night or minimize the Sun's heat by day.Wear and TearEngineers have traced stalls in a shoulder joint on Opportunity's robotic arm to a broken electrical wire. The shoulder motor has experienced greater temperature swings than other parts because of its location beside a heater that has been stuck in the &quot;on&quot; position since shortly after landing.Notes Matijevic, &quot;Our theory is that one of the wires in the electrical coil broke free and disabled the motor.&quot;Mechanical ProblemsExtremely cold temperatures have also caused mechanical problems. Recently, Opportunity's right front wheel began drawing excess electrical current, reminiscent of Spirit's right front wheel in 2004. The demand for more electrical current suggests that the wheel motor is working harder than usual. Engineers suspect that, like motor oil that can't handle freezing temperatures on Earth, gelid lubricant failed to flow properly and caused Spirit's right front wheel to fail.Adjusting ExpectationsRover drivers have compensated for Spirit's stuck wheel by driving on the other five wheels. They have compensated for Opportunity's stalled shoulder joint by unstowing it before going to sleep at night. This way, if the motor fails during the night, when temperatures are at their lowest, they would still have limited use of the arm by operating the remaining working joints. Each rover has lost a few temperature sensors as well, while dozens more continue operating.Time Will Tell
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The Mars Exploration Rover mission is part of NASA&#39;s Mars Exploration Program, a long-term effort of robotic exploration of the red planet.
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Robot Mars rover Spirit has so far been eclipsed in its mission by its &quot;twin&quot; Opportunity, which found rich evidence of a wet history at its landing site.