Slashdot Mirror
Mars Rovers' Mission Extended Another Six Months
what_the_frell writes "Looks like the Mars rovers, Spirit and Opportunity, will be online and in use for at least another six months, after surviving the lowest point of the Martian year, in terms of sunlight. New Scientist has a fascinating article on this and some of the other hurdles the rovers have tackled. It's pretty cool how the rovers have far exceeded their initial 30-day mission (today is Day 263), and that their new projected mission is now well over 365 days."
Solar panels, which they assumed would be covered with dust after a while, and not provide enough power.
Even if everything went right they still only expected the rovers to last maybe a hundred days.
The solar panels undergo a chemical reaction with the dust in the air which causes them to become less and less productive over time. (no, they can't be cleaned, the dust actually chemically bonds to the panels). They apparently overestimated the rate of this decay.
It is quite surprising they have lasted this long. Now that they have good data on how fast the solar panels actually are decaying, their current estimate should be right on the money, however a mechanical failure becomes a more likely failure mode as the parts overextend their expected lifetime by so much and this can't as easily be predicted.
Mars has a thin atmosphere.
On Earth, standard atmospheric pressure is 101.325 kPa.
On Mars, it is 0.7-0.9 kPa.
The clearance system sounds logical. It is not. It is completely arbitrary. -- John Bolton
Ok, so what part only had a 30 day warrenty, and who built it to exceed tolerances by a factor of 10?
Mars is a tough environment. The biggest problem is the wide tempurature range between day and night. On earth, thermal cycling is part of what cracks rocks into sand.
Such cycling can crack or damage electronics without warning.
Related is lubricant problems. The lubribant has to work in a wide range of tempuratures, and survive the "cooking" phase when the rovers are dissinfected on earth. One of the rover wheels seems to have lubricant problems, limiting the rover's range.
Then there is the dust that is everwhere on Mars which coats everything, including solar panels.
Table-ized A.I.
That's inaccurate. The original mission was slated to last 90 days, not 30.
Omeganon
From what I understand, it wasn't directly a money related problem, it was a weight related problem. As in, they had a set size limit for the rover itself, which was set by the size of the transport, which was set by the size of the rocket used to get it from Earth to Mars. Since it was assumed the lower inclination of the Sun after about 90 days would make the rover unable to hold a charge, they didn't figure it was worth the effort to include a broom. Of course, then, after they got it there, somebody had the idea to park it with the southern side uphill, so the panels would be more directly hit by the sun. Of course, now other stuff is starting to fail...
Have you been touched by his noodly appendage?