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Mars Rovers Alive Until 2005?
maggeth writes "The BBC is reporting that negotiations are under way to extending funding for the Mars rovers beyond this September. Originally designed to work for 90 Martian days, they now predict they may last well beyond the 250 Martian days they had announced previously." hoferbr writes "A new analysis by Phil Berardelli at the United Press International quotes Steve Squyres, chief scientist for the Mars rover mission, in which he says that the Mars rovers '... could go into 2005'. Spirit and Opportunity will complete six months on the Martian surface on July."
A Martian day is not much longer than an Earth day - 24 hours, 37 minutes as opposed to 23h, 56m.
The Raven
If anything it'll give us some good data on what Martian conditions do to hardware in the long term.
I know that right now one of Spirits wheel motors was starting to act up a bit.
As Martian "Winter" approaches, it'll be interesting to see what really cold weather does to the rovers (other than breaking them).
However, with that all said, I think we should be vigorously working on putting a colony on the Moon.
Yes Francis, the world has gone crazy.
Or conservative estimates. I've had hard drives rated for around 3000 hours that lasted more like 60000.
That would rock, but unfortunately aren't they too far apart from each other to even hope of bringing them together?
Okay, did some searching and found that at a press conference he said that the reason a mechanism was not made to clean the panels was that any ones that they could think of were not worth the extra weight that would have to be added for that mechanism.
I forget the title of the Arthur C. Clarke story, set on the moon, but it presaged another part of the problem, here.
But basically, if you whisk off the solar cell panels with a broom, you have to worry about static electricity buildup. It's just possible that by wiping the solar panel, you'll build up a static charge and attract even more dust.
Of course this possiblity suggests another possability - some sort of static device to repel the dust, so you need no moving parts, beyond deployment.
Or you just estimate the dust accumulation rate, the solar panel degradation due to that, and the design lifetime of the mission. Then make the panels sufficiently oversize to accomodate, and live with it. Don't forget that one rover already has a bum wheel, so other things are showing wear and tear besides the panels.
The living have better things to do than to continue hating the dead.
On Earth, the mean solar day is (almost, but not quite exactly) 24 hours.
The Earth sidereal day is 23:56:04.
A Martian sol is a Martian solar day.
The hardware may work or may fail, workarounds for errors may be found or not, things may be fixed, with cautious use the rovers may last for years...
Until a storm comes.
Martian dust storms come with wind at 200km/h or faster, carrying sand and smaller rocks, picking anything that isn't attached to the ground and carrying it for hours. One storm, and the rover is past, pieces of it scattered over several thousands of kilometers. And a storm will come sooner or later.
That's why there was a design of "tumbleweed" style rovers: they never deflate the airbags and let the storm carry them, letting them travel for half the planet in random direction, gathering data, until the storm weakens and leaves the "tumbleweed" in place until the next storm comes.
Current design... may live until 2005 or longer... if the storm doesn't come.
45 5F E1 04 22 CA 29 C4 93 3F 95 05 2B 79 2A B2
Bah, this reminded me off some sad news about James Doohan, he's suffering from Alzeheimer's
nasa won't get more money. The rover team is asking for funding FROM nasa.
The parent refers to the length of an Earth day when the planet's rotation is measured against the "fixed" stars (sidereal time). More precisely, this "sidereal day" is 23 hours 56 minutes 4.091 seconds. Measured against the sun, however, the length of an Earth day is 24 hours. When you use the fixed stars as a frame of reference, the motion of the entire solar system puts a little extra "English" on the spin of the Earth.
Jesus Christ. Not only did you NOT get first post, you missed it by 6 posts! I think you are the most miserable fucking failure I've ever seen. You failed it so fucking bad that it is almost a waste of my time to inform you how much you fucking failed it. If you were in the army, they would send a 4-star general to your mother's home to sadly inform her that you fucking failed it in action. Your failure is of such a magnitude that fusion energy pales in comparison. There are really no words that can describe your utter failure to achieve the coveted first post. So I will leave you with a haiku:
You fucking fail it
First post is just not for you
Death is the answer
Actually they are looking at the technology used on nascar outside cameras. The problem is that current polymers do not stand up to the increased UV light on mars and the thin film blocks more light energy than a 2 month's worth of dust on the panels will.
If we can find a thin polymer that can transmit more of the light energy and not age/yellow so fast in higher UV environments we might be able to simply "roll the solar panels clean" by roling up the thin film for the width of the panel. have enough film on the roll to be rolled up 3 times and you just extended the life of the solar panels by 3!
this is the same technology that cleans the lens on the nascar cameras and is used on motocross helmet's and goggles.. (except the helmet version is a tear-away.)
Do not look at laser with remaining good eye.
Having spent $X billion so far,...
The total cost of the Mars rovers (combined) was $820 million, including operations for the first 90 days. The extended mission - another 150 days - was budgeted at $15 million.
They didn't expect the rovers to die after 90 days, the engineers just guaranteed that parts wouldn't fail within the first 90 days. A warranty of sorts. When they launched, they said there was a good chance of them working beyond the first 90 days.
They were bad estimages, they were safe estimates. They designed the rovers to be tough enough that they would work for 3 months even under the worst situations (Like a bad landing, or bad dust storms and the like) So when none of these potentially bad things happen, the life expectancy of the rovers increases. Its like cancelling a cable substription and having them not disable your account for a month afterwards. You planned on having it terminated at the end of the month, but as a bonus you got free cable for a month.
However, with that all said, I think we should be vigorously working on putting a colony on the Moon.
Not to be a knowitall but it's actually going to be a lot easier to develop a colony on Mars than on the Moon.
- Mars has vast, known supplies of water on the poles and there's good evidence that it can be found in the ground too.
- The Moon has temperatures both a lot higher and a lot lower than Mars. That makes it harder for equipment to work and us to live.
- The Martian day is tailor made for Humans, just a little over 24 hours. The Moon has a day lasting weeks (pretty sure about that)
- Mars has an atmosphere from which we can extract oxygen with a little basic chemistry. You can crack oxygen from Moon rocks too but it takes a lot more energy.
- The Moon has a lot more radiation hitting the surface than Mars. Mars is still worse than earth but there are little baby magnetic poles to mitigate that.
I could go on and on but really the only drawback of a Mars colony vs a Moon one is the travel time. Given that humans can survive 0g for longer than the trip would take and we have proven life support systems that will work that long, all they should really need is a deck of cards to keep busy for a few months.
Blaze a trail to the New World
This has been debated a few times here at slashdot. I learned everything I needed to know from the following NASA report:
PDF file here
One of the team leads called Cartalk a few weeks ago. They asked about building something to clean off dust, and he said they get asked that ALL THE TIME. They looked at a variety of solutions, from windshield-wipers to peel-off stuff to blowing compressed air across it.
In the end, all of the solutions weighed more than just making the photocells 50% bigger to allow for dust build-up, so they did that. They were very tight on launch space and weight.
"A fall of moondust" is the story you're thinking of.
--- These are not words: wierd, genious, rediculous
Actually, if you had read any of the other five responses before posting yours, you would see that no, the leap year has nothing to do with it. Four minutes a day works out to about 24 hours per year. One revolution around the Sun produces the illusion of one rotation around the Earth's axis if you use the Sun as your reference.
The same thing happens on Mars, but because it's year is about twice as long, the effect is about two minutes a day. If you measure time relative to the position of the Sun, then a Martian day is 24 hours, 39 minutes, 35.24409 seconds.
Mars Time FAQ
No, you still missed the point. Those four minutes are the phantom rotation caused by the revolution. That produces one day per year.
A leap year is because a revolution takes about 365.25 days. That makes a calendar with an integer number of days per year slip by about a day every four years, hence leap years. This is a separate effect.
It was probably a case of not knowing what the "weather" would be like up there. Excessive winds carrying dust and small stones could easily damage parts of the rover, rendering it inoperable, hence the conservative estamate.
DarkMantle I been bored, so I started a blog.
The mechanics for the rovers were built inhouse at the JPL in Pasedena. JPL has a rather extensive machine shop with many expert machinists trained for exactly this kind of thing. As far as the instrumentation, several parts of it (such as MINI-TES) were developed at other universities, then integrated at the JPL facility.
Unlike the two previous failed missions (Polar Lander and climate orbiter) which were built under contract with rockwell, these were built in-house, so as to avoid the problems that sank the previous missions.
...si hoc legere nimium eruditionis habes...
Not to be too trollish, but if you are building a bridge to hold 10 tons and it ends up holding 100 tons, you are wasting resources.
That's easy enough to do when you're doing something that's been done thousands of times before. Very difficult when breaking new ground (so to speak). And, to stick with your bridge theme, its the reason that the Brooklyn bridge is still standing when almost none of its contemporaries are. The designer realized that he was going beyond the bounds of his experience and the current state-of-the-art (as the rover builders did), and intentionally overengineered it - not to compensate for the factors he had already taken into account, but to give it a fighting chance against factors he didn't even know existed. Same goes for Mars, doubly so because there's no hope of a mid-project refit.
You're special forces then? That's great! I just love your olympics!
Bill Nye (the science guy!) sat on one of the committees when they were designing the rovers. I got to meet him afterward and ask him a few questions.
I asked: If the rate limiting factor is the dust build up on the shields, why not have windshield wipers?
The answer: They've tried just about all of those sorts of things. Or at least thought about them. But suppose you have a wiper mounted on a mechanical arm. So now your solar plates will be always dust free, because the wiper brushes them off. But eventually dust will work itself into the joint in the mechanical arm. And the arm won't drag across the solar panel, and that's that.
So why not use compressed air? Well, an air tank will eventually run out. And the same problem occurs. Use a fan? Dust will clog the propeller, and then the solar panels.
The basic answer is, "if things move, they'll eventually stop moving because of dust." And things that move are a) heavy and b) expensive and c) can break down. So in the interest of engineering, they abandoned them all.
An interesting idea was "molting" solar panels... Mount a second set underneath the active ones. When the active panels are coated with dust, just drop 'em off. But that makes it bulkier, heavier, less efficient...
There's basically no "good" tradeoff; to extend the life of the panels, your weight and cost and complexity go up. Period. And the goal is to minimize all of those three parameters, so, we have the solar panels we have.