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Long-lived Mars Rovers to Keep on Roving
An anonymous reader writes with a link to a ComputerWorld article about the ongoing saga of the Martian rovers. They've overcome amazing obstacles and they show no signs of shutting down any time soon. "'After more than three and a half years, Spirit and Opportunity are showing some signs of aging, but they are in good health and capable of conducting great science,' John Callas, rover project manager at NASA's Jet Propulsion Laboratory said in a statement. Since landing, the rovers have had to surmount a host of technical issues. Just a few weeks after landing, the Spirit rover had an out-of-memory problem that almost ended its mission before it began, but scientists were able to get the rover back into operation. In April 2004, both needed software updates to correct problems and improve their performance."
Such a rover would be so big and heavy, it would never make it to mars. In order to make sure the rover will last for a couple of months given everything that could possibly go wrong, it has to be so over engineered, that odds are it will last many years.
Or to put it in numbers, a 99.99% chance of surviving for 3 months, could easily translate into a 50% chance of lasting 5 years.
It just seem so to you, because you hear only of the spectacular missions. Routine missions aren't really interesting news.
You have to admit that over these three years it hasn't been very many scientific accomplishments they didn't do in the first three months
I think its too early to say that. They still don't know when the water was there, how long, and how much. That's gonna take a lot of time-consuming study of a lot of details. Scientists are still discovering new things in Viking data.
Now we know you can keep continous solar power working on Mars, and that'll be the expectation from now on.
The whirlwind effect is kind of hit and miss, though. A device that depends on solar power may have many months of down-time if a whirlwind fails to show up. And as we've learned, big dust storms risk freezing the electronics to death. Thus, solar is still risky.
I figure they're already using pretty much the best they got.
I've heard there are known spots that lack redundancy on the rovers. A more expensive mission could potentially have more areas of redundancy.
Table-ized A.I.
They jus' keeps scoopin',
They don't have scoopers, by the way, at least not in the Viking sense. They take the instruments to the soil instead of bring the soil to the instruments.
However, they can and do use their wheels to dig small trenches in order to analyze deeper soil. They do this by holding 5 wheels mostly still and move the 6th wheel.
It is a remarkably compact yet flexible way to get the most out of existing hardware.
Spirit cannot do this well anymore because of one stuck wheel. However, by dragging it around, it has become a happenstance "auto-trencher" and because of it they've stumbled upon some soil with high salt content underneath the visible layer that many scientists think is an important clue to the continuing water study (although the pieces to the puzzle still have yet to be all fit together). Now they regularly do spectral analysis on the bum-wheel trenches to see what's below the visible layer.
Table-ized A.I.