Mars rovers struggle with sandy slopes, solar winter
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Opportunity, one of NASA&#39;s two Mars rovers, struggled to get up the side of Endurance Crater. It spun its wheels, digging deep holes in the stadium-size crater&#39;s &quot;sand trap.
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A raging dust storm on Mars has cut power to NASA&#39;s twin rovers to dangerously low levels, threatening an end to the mission.
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NEW YORK Aging but still on the go, climbing in and around craters, tapping into the mysteries of strangely cracked rocks, the two roving vehicles Spirit and Opportunity have explored Mars about three times as long as originally scheduled and keep finding
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Scientists analysing data from the Mars exploration Rover missions believe water was involved in the formation of rocks on the planet.
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Mars rovers have found new evidence that water was once plentiful in the hills and plains of the now-barren Red Planet. After discovering the plains where it landed was once a
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The Mars rovers emerged from a communications blackout period and the low point of winter today with new funding and big plans for the journey ahead.
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NASA will send its Mars rover  Opportunity into a gaping Martian crater in July to seek clues  about the planet&#39;s bygone environment despite risks to the  plucky little vehicle, officials said on Thursday.
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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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In the next few weeks the twin Mars rovers will be out of touch with Earth when the Sun lines up to block communications. Daily operations will be taken over by longer-term instructions without radio links between the two planets.
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An unexplained phenomenon akin to a space-borne car wash has boosted the performance of one of the two U.S. rovers probing the surface of Mars, New Scientist magazine said on Tuesday.
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NASA&#39;s Mars rovers don&#39;t seem to be wearing out so mission planners have begun to think more boldly, including a plan to let one climb up a steep &quot;escape hatch&quot; from a crater it has been exploring and set out on a trek across a plain.
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The hardy Mars rover Opportunity is struggling to stay alive  amid a severe and long-lasting Martian dust storm -- posing the greatest threat so far to the unexpectedly long-lived vehicle.
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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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The twin rovers  on Mars are in good shape today despite widespread dust storms that worsened last week  and threatened to cut off solar power to the robotic explorers.
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Mission scientists worry that nearly a month's worth of storms could permanently damage or disable the Mars rovers exploring the Red Planet.
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By Alicia Chang, The Pueblo Chieftain, Colo.  Feb. 2--LOS ANGELES -- Scientists are scrambling to find an alternative landing site for a long-armed robot set to launch this summer on a mission to dig into Mars' icy north pole to search for signs of primitive life.
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LOS ANGELES NASA&#39;s Mars rovers continue to perform, working three times longer than their designed lives and prompting controllers to give them additional chores.