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Mars Rovers Threatened By Dust Storms
mrcgran writes "Space.com is reporting a new potentially deadly weather condition threatening the Mars rovers: 'The first and largest dusty squall has reduced direct sunlight to Mars' surface by nearly 99 percent, an unprecedented threat for the solar-powered rovers. If the storm keeps up and thickens with even more dust, officials fear the rovers' batteries may empty and silence the robotic explorers forever. "This thing has been breaking records the past few days. The sun is 100 times fainter than normal. We're hoping for a big break in the storm soon, but that's just a hope." '"
They have. The problem is that the batteries also are providing power for heaters to keep the rover warm during the night. They probably won't (especially the batteries) survive a deep-freeze to -40C, so when sun starts shining again there may be too many things broken to start the rover up again.
Then the storm came for Kingston upon Hull, but I live on a hill on the other side of England and it did not worry me.
Then the storm came for the Mars Rovers, and I was really quite worried about them. What a relief to know that I'm not sociopathic.
Pining for the fjords
Damm trans-global warming, ever since Al Gore invented it there has been nothing but problems, look even Mars is having problems now with record storms.
09-f9-11-02-9* (G^GCA_++{>. RV>>>>+++ NO CARRIER
So, its not that the battery won't come alive again later. Its that the cold will do serious damage to the electronics on board. Without power, there's no way to keep them warm. Nights on mars go well below -25C (in the winter, the southern hemisphere can get as cold as -120C).
I'm sure they could have guaranteed that kind of functionality inside of there original 90 day design lifetime. Here we are 3 years later and they're not sure.
I think the designers deserve some credit. If you feel you can do it better I'm sure NASA would appreciate your resume.
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From TFA:
OK then, *you* go turn them back on...
Even if it is the end the people who designed, built, tested and watched over those rovers over the past years should be very proud of their accomplishment. To succeed so well at something that is so incredibly difficult is high praise in itself.
To these talented and hard-working engineers, technicians and researchers (and even the JPL PHBs), I salute you.
Problem is they used an embedded windows product, and an evaluation one at that (Embedded Windows XP rover edition) it requires you to press any key upon boot up to agree to the Beta license.
The rovers will boot but wait for someone to hook up a usb keyboard and press enter.
They should put stuff like this on Mars:
t s
http://www.ecogeek.org/content/view/350/
( Saw them on digg:
http://digg.com/gadgets/Amazing_wind_powered_robo
)
These machines were designed to last three months. They've lasted over three years. They never expected them to last long enough for it to matter.
It's probably wise not to second-guess engineers who built something that lasted more than ten times longer than anyone expected.
The cake is a pie
while this is unfortunate, nasa expected a failure such as this a long time ago. They have been invaluable source of knowledge-- and i'm sure they won't be the last rovers on mars.
"KEYBOARD NOT FOUND. PRESS F1 TO CONTINUE"
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The difference being that almost no light for too long of a period of time, not allowing the rovers to keep warm. They've always used batteries & solar power to keep the circuitry just warm enough to keep them from being damaged. Without that warmth, circuits can crack.
(2) if there is sand on the solar panels, you can't get power to wipe the sand off
--
For some reason there ain't no method to wipe the sand off, apparently that's one reason why they thought they would last only 3 months.
Why no wiper is beyond me though.
Tinfoil hats and all.
Reminds me of my Rover. That was obviously designed to last 3 months.
I don't think so. There are no extra-terrestrial rovers that have lasted 90 days that I remember. One Soviet lander lasted 20 seconds on the surface. Sojourner lasted 83 days. If you know of any counterexamples, please let me know. Otherwise, your explanation is implausible because one year or three years is far, far longer than anyone has managed and is unrealistic.
The problem is that they expected the solar panels to fail due to excessive dust collection, blocking the light, and they had found no economical means to clean the panels. They got lucky when an occasional wind storm cleaned off the current rovers.
wire wrap is nice if weight is not a problem. In a launch, every gram matters, and wire wrap adds a lot of weight for several reasons. You have to have posts to wrap around, you have to use fat solid wire instead of thin traces, and the runs of wire are longer than the traces.
Size is also important. Wire wrap boxes are usually very large by comparison with a soldered PCB, especially where there are dense electronics. These rovers probably have several surface mount ICs on them, and you can't wire wrap that.
Also, correct me if I'm wrong here, but the longer the connecting traces/wires are, the more likely they are to be hit by EMI etc? So longer runs of wire, in addition to adding weight and bulk, could also invite unwanted and potentially damaging inducted power.
It appears they made all the right choices with the amount of information they had to go on and the design goals they had to meet. I can't think of any other possible way to explain the level of their success as discussed by numerous previous posts.
iirc, the rovers were scheduled for three months, and that's before ANY winters. The thing was designed to work for less than 1/2 yr, in the summer, but they engineered it with the "possibility" of surviving a winter or two. How may winters have they made it through so far? If it finally breaks, think of it like your car lasting you 40 years before you have to replace it. It owes you nothing, be happy for what you got, it's more than you deserved.
I work for the Department of Redundancy Department.
The problem is that the dust on Mars has an electrostatic charge. Wipers would just swish the dust around and scratch the solar cells, but wouldn't be able to remove the dust.
At Mars Exploration Rover Mission there is still no official statement that the Rovers are no longer operating normal. It seems that this site is not always up to date, but if I count correctly, images from the Rovers are still arriving. The last status report of Spirit is from June 2, for sols 1234-1239. The last Spirit images are from Sol 1247. The last Opportunity images are from Sol 1226. If I counted correctly, that must have been yesterday or today.
Age is compounding the problem. JPL has a good article up at http://marsrovers.jpl.nasa.gov/spotlight/20070612. html.
What you do with a computer does not constitute the whole of computing.
As someone who actually builds things for extreme environments (including Mars), I call BS. Soldering is potentially MUCH more reliable than wirewrap, it's all in the design. Not to mention there are some size and mass restrictions on something that has to be sent to Mars by rocket. You were, perhaps, thinking of wirewrapping the thousands of pins on a multihundred pin FPGA? Oh yes, that wirewrap socket for the part doesn't exist.
But there are a host of other issues. What about glassification temperatures? What about various polymers needed?
There are Radioactive Heating Units (RHUs) to keep the Warm Electronics Box, er, Warm, but there are things on the rovers that aren't in the WEB (wheels, pan cam mast, Xband antenna gimbal) that aren't RHU compatible.
Ultimately, it comes down to cost. How much is Congress willing to spend? Are they willing to 10 billion instead of 1 billion to send a couple rovers to mars? At some point, someone has to say, here's our design life, here's our mission environmental requirements (typical flight hardware would be -55 to +65C), and design accordingly. It's a judgement call, and the folks making that call DO have experience from the 60s and 70s (sometimes to their detriment.. it's hard to get new technology inserted)
The rovers were supposed to last only three months because of dust building up on the solar panels---how come they never considered wipers?
Considering the fact that the rovers have far outlived their design life - wipers don't seem to be essential, do they?
Wipers (and the motor to run them) add mass, the motor requires energy, circuitry, etc. Just another component that can fail. And a non essential one at that, apparently.
Seven puppies were harmed during the making of this post.
Actually, no. It was designed for three months. They, of course, made any changes that might make it last longer that didn't effect the budget, but they very definitely avoided any design improvements intended to lengthen it beyond 90 days, unless those improvements cost no money. The budget was very tight and many potential design improvements to make the rovers last longer were specifically rejected. (See the book by the project lead.)
The cake is a pie
A few points:
1. How much is your "other power source" going to weigh?
2. How much is your "other power source" going to cost?
3. Does your "other" power source comply with international environmental/space regulations?
4. How many failure modes does your "other" power source have?
Seven puppies were harmed during the making of this post.
MERs and other Mars surface landers and rovers don't use wind turbines because the atmosphere is incredibly thin - far to thin to turn turbine blades. Think about it... they've only received puffs of wind strong enough to blow the thin coating of (incredibly small) dust particles off the solar cells half a dozen times in three years. You'd barely feel the touch of the wind on your skin even when it's blowing at it's strongest.
Everything I needed to know about life, I learnt from Blake's Seven
Am I the only one to find the timing of the freak "dust storms" suspicious? It is obvious that Martians living in the neigbourhoods currently explored by the rovers would have a hard time launching to attend the Roswell UFO festival without being noticed. And you know some of these Martians value their privacy. I am sure these "dust storms" will clear out after the weekend, when everyone's back from the Festival.
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Not having searched, I wonder what power source the Rovers use? Were it a small backup nuclear battery it would surprise me if it couldn't keep things (like the main batts) warm enough, and last long enough to power the most basic of rover "keepalive" functions.
Also not knowing how much wind is actually whipping up the frothy dust, how big would a set of cups or blades on the ends of a stick need to be to generate power for the same purpose (if not nuclear). Granted one couldn't always count on there being wind, and the cost to weight ratio against the advantage of having a wind power backup might not add up - but it begs the question...
Never have a philosophy which supports a lack of courage
Dust storms on Mars are a known risk. If the dust storms were this bad on the planet when the rovers first landed, the rovers may not have been able to last past the original 90 day mission. Everyone at NASA/JPL will tell you that luck has played a significant role in the current longevity of the rovers due to the lack of dust storms to date and the various cleaning events.
The current rover design can't be used when investigating Mars outside equatorial regions, either.
It's been a great run for both rovers, and it's great to see them provide atmospheric data on opacity of the atmosphere (tau) -- measuring that which may ultimately kill them.
Might I suggest that the engineers may have insisted very thoroughly to others that they were designing for 90 days, but really they were designing for much longer. Might I suggest this essay: Exaggerate with Extreme Prejudice.
--JoeProgram Intellivision!
1. Install wipers for the solar cells.
1) The wind from the storm has (once again) actually CLEARED the panels of dust.
2) The problem is that the storm is cutting out the sunlight used to charge the rovers. what would your "wipers" do, reach into the upper atmosphere and clear it out? Or perhaps they should have added an arm to hold a flashlight pointed at the solar panels. Genius!
"There is more worth loving than we have strength to love." - Brian Jay Stanley
I believe you are confusing surface winds, which are very light, with atmospheric winds which are much faster and more then capable of blacking out the sun.. just because energy is up there, doesn't mean you can effectively harness it.
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Lunokhod-2 lasted for four months and explored 37 km in 1973.
Opportunity has survived -54 degrees when in Deep Sleep mode.
National Geographic reported a day later that the storms are not a threat: http://news.nationalgeographic.com/news/2007/07/07 0706-rovers-dust.html.s -selling-solar.html
--
Rent solar power: http://mdsolar.blogspot.com/2007/01/slashdot-user
Once upon a time all prototype electronics were wirewrapped. Today, it's a dying art.
When dip IC's ruled the roost wirewrap was king. Today, surface mount ic's are king
and pc boards rule.
Also as circuit speeds went up, wirewrap stopped working. With clock speeds under 5 mhz, the long leads of wire wrapped construction with signals running parallel worked well enough. With today's 100mhz+ clocks wirewrap would have fatal crosstalk. Back in the 80's a company I worked for tried to wirewrap a cpu prototype using 10mhz processors. We NEVER got it to work, too many problems with crosstalk. A 4 layer circuit board was MUCH quieter, and worked fine.
Then there is the issue of labor. With computer layout software and automated fabs it's much cheaper and faster to have a pc prototype made than to pay some tech's to wirewrap a proto. In fact you can go through two or three pc prototypes in the time/money required to do just
ONE wirewrap one.
Wirewrap is DEAD. Bury it!