Keep on rollin'...
Top work little chap. Good work NASA.
It has been the week of long-lived space hardware: first came the news of Voyager 1's thrusters working after 37 years without use and now NASA's cautiously suggested that the Opportunity rover on Mars will be fit to roll into its 14th year of red planet operations. Two big threats imperil Opportunity's ongoing operations. The …
That's what you get with dedicated, passionate and well trained engineers, something that can survive harsh off-world climates year after year.
Meanwhile back on earth some software "engineers" still can't write simple software that doens't have a shed load of security holes and puts lives at risk!
'When Elon is going to send that Roadster to orbit Mars, perhaps he could put a couple of spare windshield wipers in the trunk to drop off when over Spirit and Opportunity.'
Joing aside, does anyone know if they ever thought of including something in the design to keep the panels clean? I've always thought it was a bit of an own goal not to, but I'm guessing they had a pretty good reason for not adding some wipers.
Weight, extra moving parts (you really don't want a wiper or brush to get stuck halfway across a panel) and I think the amount of dust collecting on the panels was one of the things that was quantified by Spirit and Opportunity. Previously the amount of dust expected was "some".
I think weight, complexity and lack of necessity for the original mission are all right.
But also Martian dust can be quite sticky due to static so maybe a brush just wouldn't work anyway of might cause electrical problems etc. Things don't always work as expected in these (to us) extreme environment.
"I'm guessing they had a pretty good reason for not adding some wipers."
no refills for the windshield washers?
without water, it would probably scratch the surface of the solar cells. I can't imagine anything worse than wiping sand across a glossy surface with a slightly brittle wiper blade and no washer fluid...
"Joing aside, does anyone know if they ever thought of including something in the design to keep the panels clean? I've always thought it was a bit of an own goal not to, but I'm guessing they had a pretty good reason for not adding some wipers."
Pretty in-depth response from the mission manager below. Short version, they wouldn't have taken the dust off, they'd have damaged the cells and there was a far simpler solution for the scope of the original mission - make the panels slightly bigger than required to mitigate the issue.
It's a FAQ over at unmanned spaceflight.com . You have to remember that any mechanism you add has to have its mass balanced by taking something else off. Mossbauer? RAT? It would also be something else to go wrong. For a vehicle designed to last three months, it wasn't worth it.
I remember pointing out Mars to my boys years ago, explaining how they could tell it was a planet because it wasn't twinkling, and how to recognize it was Mars by its red colour. A thought struck me and I told them two robot cars (Spirit and Opportunity back then) were driving around on that little dot in the sky, and their jaws dropped. They were already well beyond the 90 days at the time. Amazing to think Opportunity is still going strong. Excellent engineering!
True to a certain extent, I think. 90 days was the primary mission objective, and would have been achieved for the nearly-worst-case situation for panel dust collection. Everything else was massively overengineered against the 90-day objective because it was known that the level of dust collection might not be worst-case.
I doubt that anyone seriously thought they'd get away with it for this long, though.
icon: Go - and keep on going.
"They clearly designed it to last years. Probably could have survived 90 days without solar panels"
If you had built a device with an 80% chance of lasting 90 days, then as well as standing a 20% chance of dying during the initial period then statistically it's pretty certain it'd now be dead.
However, if you spec a device to have a 100% chance of surviving 90 days, that gives a very, very high statistical probability that it will still be running for many multiples of that time.
That it has lasted as long as it has though is more or less pure luck. If storms didn't periodicly blow the solar panels clear(er) then it'd be dead long ago from dust buildup on the solar panels. Since we didn't know about the storms before it's not something that could be planned for or expected.
Potatoes? Surely not - those are the things that primitive earth people peel with metal knives then boil in water for twenty earth minutes then smash all to bits ... Martians have a much more advanced cuisine.
According to a Mars documentary that I watched, they apparently mix vicodin in with theirs.
Mine's the one with all the prescriptions in the pocket.
> Could someone suggest an idea of the size of the rocks in that photo, wrt to Opportunity?
If you follow the link in the photo caption to the NASA site, they give the size of the full image, which is about 3.5m (metres, not miles). The cropped image used in the article is maybe 0.5m.
it is hard to beat it's historic generosity to man (and woman) kind in all the benefits we have derived from President John Kennedy's decision back in the day.
From Teflon to eye-popping pictures from Hubbel , adjustable smoke detectors, artificial limbs, baby formula, cell-handset cameras, computer mouse (stolen by Jobs), cordless tools, ear thermometer, firefighting equipment, instant dried food (far better than Army field rations of past years), invisible braces, transformational distance communications, foams and glues, MRI and CAT scanners, boot insoles, skiing boots, solar devices, UV-blocking visual aids, water recycling and purification filters. (I am sure there are more on Google)
And a Thank You to American Taxpayers who made it all possible.
When Curiosity's nuclear battery runs out.
RTGs generally deliver useful power for decades, based on the Pioneer 11-12 and Voyager 1 & 2 examples. I'd expect something else would give out on Curiosity first, like its wheels, batteries, or flash memory.
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