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Rovers May Survive Martian Winter
yokem_55 writes "According to this article on Yahoo News, Mars rover engineers are beginning to consider the possibility that the rovers may be able to survive the oncoming Martian winter in a hibernation mode, and then return to activity when spring returns to the red planet. The article ends with a quote from Steve Squires speculating that, 'we're looking at the final demise of these vehicles perhaps as late as the onset of our second winter on Mars.'"
I don't think that there's enough solar energy during a Martian winter...
-Ashton
Always nice to see the reminder that NASA can do great fucking engineering when the mission is properly separated from politics.
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Mod me down, you fucking twits. Go ahead. I dare you.
(I read with sigs off.)
A dust cleaner would be another thing that could fail... as would anything else to extend the mission time frame. Instead of a more complex system that could run a year, they made a simple system to last a couple months. Simple seems to be a really good thing when you can't go over and kick it if it gets stuck.
--
Evan
"$30 for the One True Ring. $10 each additional ring!" -- JRR "Bob" Tolkien
Does anyone else get the feeling that the rovers were actually designed to last this long, but the lifespan that was published was a PR version that was extraordinarily short, so that in the event the rovers didn't last this long, they could save having to answer questions?
... until after we've had the experience to back up the assumptions made about the longevity of the hardware.
Yes. Two words: Insurance Policy.
NASA can't keep paying insurance on the rovers for years and years, so they plan (in the budget) for limited life times. Set your targets low, get as much done as you can within the limits of those targets, and get out.
But we should never forget that our estimations for how long things last are completely arbitrary
The lifetime of the rovers is not so much about science as it is about beauracracy and politices, and ultimately 'responsibility'.
Personally, I don't see why we just kick out the beauracrats entirely, throw all Insurance premium mafia ripoffs to the winds, and build harder rovers.
Maybe we don't need to keep going to Mars, maybe we just need to 'learn to stay there' technologically longer than our society is currently capable of supporting. (Insurance is a 'society' thing, it isn't technological...)
; -- the corruption of government starts with its secrets. a truly free people keep no secrets. --
These things are engineered to last a certain ammount of time, as component specifications are generally conservative equipment will often last longer than it was designed for.
Take the voyager 2 probe, this was launched with the intent of exploring Jupier and Saturn. But they managed to extend the mission out to both Neptune and Uranus.
Of course they thought about these posibilities, they chose the launch date such that they could continue their slingshot in that direction :-)
I know i'm asking for the imposible here, but couldn't you have read the article first before asking us to spend time telling you things that are already in the article? WTF makes our time so cheap, and you so precious that we have to digest this short article for you so you dont have to read it!
Anyhow to awnser your question, allow me to quote the article: "Part of the wintering over strategy will involve positioning the rovers to soak up as much continuous sunlight, even as the Sun moves low in the martian sky, Bell said. Secondly, the robots are to be oriented so that communications links with orbiters zipping overhead is maximized, he pointed out."
In otherwords, they will go into low power mode, but not be switched off, and hopefully be positioned so that they wont loose communication for very long, if ever
Try
Approximate round trip times in milli-seconds:
Minimum = 9000ms, Maximum=10000ms, Average=9100ms
The article doesn't go into enough details, but I would think that even in the worst Martian winter the solar panels would generate *some* power, with battery backup for the worst storms.
You're right to say that if you were to keep in continuous radio contact it would use too much power, but waiting for the spring and then getting into radio contact shouldn't use that much power. After all, the rovers will have been in hibernation for many months on the journey to mars.
"As a writer / novelist you might want to spellcheck your sig.
Reminds me of a Scotty quote, I can't seem to find it online, but it had something to do with him always telling the captain that it would take 10 hours to fix something when it would really take 5, so when Kirk told him to do it in 5 it would make him look brilliant. The rule of halfs I guess. But what if your superior asks for it in 4 hours? I guess you're screwed then.
Even those who arrange and design shrubberies are under considerable economic stress at this period in history.
As compared to a capitolistic society where companies always overstate their goals and products just incase their compeditor does the same. Its interesting that we have two sectors: the government, and free enterprise; and they both have similar goals- be profitable, provide for their 'customers', remain in business. And they have evolved to completely opposite tactics, in some cases.
I'm sure there are some companies that don't overstate their products, and I know that some government agencies do, But there have been plenty of times I have gone to X government agency and been surprised at all they can do for me, and lots of times products have not lived up to expectations.
Even those who arrange and design shrubberies are under considerable economic stress at this period in history.
Tell that to the Beagle guys. Just the fact that we landed both of them in the first place is an accomplishment.
I think they could both be in the northern (or southern) hemisphere and still be on opposite sides of the globe. Eg, Russia and Canada or Australia and Argentina.
Getting solar to work on these spacecraft with the intent of using the spin-offs here on earth is overkille, and expensive overkill at that. Even if you develop solar cells efficient enough to make a household self-sufficient as you suggest (which still makes me nervous about all the batteries you'll need lying about), there are fewer watts per square meter to work with the further out from the sun you are. You'll get to the point where the solar cells and the associated batteries are the most expensive components of the mission, ultimately getting in the way of the goal of the mission itself.
Solar works well for Mars and closer, but once you get to Jupiter and beyond it just isn't a realistic option. Imagine giving Cassini two solar arrays, each 9 meters by 32 meters. JPL has, and and they've got diagrams.
And I personlly believe nuclear power sources are more environmentally friendly than all the batteries you'll need to get you through those long, dark winter nights.
"Set your targets low"
Yeah go to another planet more than 300 million miles, land safely do a whackload of experiments, travel around on the surface for miles, transmit all the results and pictures back flawlessly and while driving on Mars have multiple feature enhancements added...
I guess project management is a skill you have yet to aquire?
NASA also used to historically "overbuild" these machines to as much of a degree as they possibly could too, within the bounds of such parameters as launch weight, power consumption, budget, etc. Surely these "overbuilt" qualities are a significant factor in the machines' ability to far exceed their original intended missions.
Nowadays, the beancounters have much more say over the engineers, and the "overbuilding" is done to a much lesser degree.
NASA does a ton of incredibly good things to encourage science and technology.
They supported over 30 FIRST teams when I was in FIRST - I would bet they support more now. Look at the link, it's an incredible program. If possible, get your company or school involved in it. FIRST was one of the best experiences of my career.
Note: FIRST stands for:
For
Inspiration and
Recognition of
Science and
Technology
Sticks and Stones may break my bones, but copyright will always protect me.
"No Seriously why dont they just use disposable lens covers, like they make for motorcycle visors... when it gets covered with crap, just use a little robotic arm or something to remove it."
Why does everybody assume they thought of something that NASA didn't?
I'm thinking isotope decay power sources would be a bit better. They power satellites, why couldn't they power a rover?
damn politics getting in the way of science.
There is enough wind on Mars, even with the extremely thin atmosphere, that it's possible the dust will stop building up before the power output of the cells drops below the amount required to run the rovers. Even at reduced cell output, the rovers could be run on a day-on day-off cycle (for example) until the batteries can no longer hold a charge or the cell output drops below what is necessary to charge the batteries.
The point I think that NASA is making is that their predictive models used fairly pessimistic assumptions as to how badly the solar cells would degrade over time, and the actual cell performance and dust coverage is proving to be better than their predictive models anticipated. That plus the fact that they've managed to almost completely overcome the relatively few hardware failures suffered so far, is grounds for being optimistic about the rover's lifespan.
The flip side of the coin - somewhere a budget analyst is kicking himself because he let the engineers talk the rover team into building in excess power margin based on a more pessimistic prediction on solar cell dust coverage. In a "perfect world" according to the budget people, they'd spend only enough to ensure that the rover dropped dead the day AFTER it completed the planned mission. It now looks like they apparently overbuilt the rovers based on what's happened with the 2 rovers at widely separated mission locations, and that's bad news for whoever controls the checkbook. Hopefully the next set of landers won't fail prematurely due to a redundancy or excess margin backlash because of how well these rovers have performed.