Mars rovers ailing more and more with age, still amazing robots

Posted by NewScientist

Mars (4th rock from the sun) - NewScientist's David Shiga is reporting that NASA's Mars rover vehicles, Spirit and Opportunity, are suffering more and more problems four years after they were initially deployed.  The latest failures are a blinding of one of Opportunity's infrared sensors, along with a defective rock grinding tool.  The infrared sensor became covered with dust.  And there are many more failures on the list.

Spirit had one of its front wheels lock up in March 2006, due to a defective motor, causing it similar navigation difficulties.  They've had to drive it in reverse to compensate.  One of Opportunity's front wheels stopped turning right or left in 2005, though it is still able to rotate and provide power when moving.  There have been several other component failures in sensors, analyzers, on-board software, etc.  None of these have proved fatal though.

Takes a licking...keeps on ticking
Even with the numerous failures on both rover vehicles, their life expectancy at the time of the project's launch was only thought to be about 90 days.  Scientists feared dust would accumulate on their solar panels, preventing them from receiving enough of the sun's energy to maintain adequate warmth to keep its delicate components from damage through the cold Martian nights.  However, the Mars atmosphere has actually helped both rovers along as periodic gusts of wind blow the dust away, allowing them to make it through even the coldest winter nights.  Additional concerns were over the life of the high-amperage batteries, which have also performed significantly beyond all expectations.

Spirit and Opportunity continue to remain in contact with NASA, sending back valuable scientific data.  They are responding to commands and the project is undoubtedly hailed by NASA as one of their biggest successes.  With an initial life expectancy of 90 days, some four years later it seems Spirit and Opportunity have proven they are definitely full of spirit and opportunity.

Author's opinion
I have always had a good feeling about the way NASA has been able to obtain so much data from Spirit and Opportunity.  I've enjoyed reading about the progress of the two little vehicles, each about the size of an average office desk, little more than very expensive go-karts really, that have now traveled several miles on the Martian surface, and without significant incident in doing so, Spirit driving 4.51 miles, Opportunity driving 7.19 miles.

Messages to and from Mars take up to 12 minutes each way, depending on position in orbit.  To put this into perspective, imagine trying to successfully navigate a remote controlled car here on Earth right in front of you when, after sending it commands to move forward, turn right, left, etc., you'd have to wait 24+ minutes before finding out what it did.  All in all, it's a very impressive feat of coordination to achieve as much success and data as they have, given the huge distances involved.

Read more ... NewScientist.