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Mars Rovers Update
BoldAC writes "CNN is reporting that engineers will upload a software hack to decrease the recent power drain plaguing the rover Opportunity. The hack works by reducing the power supply to a poorly functioning switch." p3tersen writes "Opportunity has photographed a blue martian sunset (it's blue because of the optical scattering properties of dust in the martian atmosphere). In other news, the rovers are beginning to experience power supply problems due to the accumulation of dust on their solar panels."
Every easy solution has a problem. The problem with this one is that the Mars rovers don't have any arms to rip the layers off.
The dust problem is just indicitave of how difficult it is to plan such a complex mission like going to Mars. Until we do this a few more times and figure out a few more things, a manned mission will have to wait.
a fan would be overly complicated and would draw too much extra power at 1% of Earth's air pressure. Why not just add peel away layers (like a cleanroom tacky mat) of transparent plastic to the panels? A tiny motor would be enough to reveal a new layer now and then. It's hard to believe they didn't try to think of something like this or simply didn't care about the dust problem.
- "Hear that?! The percolations are imminent! Cease your ingress!"
I wasn't referring to the articles referenced in the story. I was referring to the Slashdot story itself:
"CNN is reporting that engineers will upload a software hack to decrease the recent power drain plaguing the rover Opportunity. The hack works by reducing the power supply to a poorly functioning switch." p3tersen writes "Opportunity has photographed a blue martian sunset (it's blue because of the optical scattering properties of dust in the martian atmosphere). In other news, the rovers are beginning to experience power supply problems due to the accumulation of dust on their solar panels."
Dan East
Better known as 318230.
How is the motor supposed to pull the correct wire (you wouldn't use thread)? Ten different motors?
What do you do with the tear-off once you pull it? Leave it clumped at the bottom or just have hang around trailing behind the rover or right on top of the panels? Cut the wire you say? Kind of difficult to do that if you rolled the wire up on a spool with a motor. Going to need ten pyros for that.
Don't forget that you have to pack all of this onto the rover and fold up the panels. Better hope your wires don't tangle up and prevent the panels from unfolding.
All of this stuff takes up weight and adds complexity. Do you really want to do all of that?
1. It's going to weight more.
2. It's another potential failure.
3. IF it fails, it can cause other things to fail (say, for example, a switch sticks ON and it drains the battery)
Not installing a wiper or other device to clear the solar panel wasn't an oversight. They made a (probably) well-informed decision not to install such a device. I think the progress so far is remarkable and should be commended. Hopefully they've learned a lot and can make improvements for the next mission.
Hindsight is always 20/20...
If the dust is electrostatically charged, what would be involved in covering the solar panels with a thin, transparent film or network of wires that is itself charged to repel this dust?
Am I the only one who heard Roxette to sing "I'm gonna get blitzed for some sex"?
Use a Vibrator! No Really!
I've been reading all the other posts, Every idea from peelable plastic sheets to fans..
Just attatch a vibrating motor to the underside of the solar panels. When it's time for them to get clean, just raise them to a 90 degree angle, turn on the "orgasmotron vibrating motors" and shake the dust off?
Maybe I watch too much pr0n, but I'm sure that would work for the heavier dust. Especially since there was an earlier comment on how the engineers purposefully drive these things over rocks to shake off the larger dust particles.
One more thing, movable solar panels can track the sun, and give better light collecting efficiency than ones that just sit there stationary.
--toq
How does testing the software determine the heater is going to malfunction?
Given CNN's lack of technical depth, for all we know it could be a command to the rover to tell it not to turn on the heater anymore. Either way, they designed the rovers so they can fix them while they're in space, which is pretty good.
Given the limited amount of storage on the rover, it's a higher priority to make sure the upgrade process works, and that it is possible to fix stuff with software, than to make the rover fix stuff automagically.
Need a Catering Connection
A thread attached to a corner of every plastic sheet running diagonally to the opposite corner and an electric motor that activates when the sheet is dirty.
Stack 10 sheets of this and voila, lifetime of the rover multiplied x10.
Conceptually, this is a great idea, except for one problem:
Every layer of $whatever you put on the panels attenuates some of the light striking the panels. The sunlight is also that much dimmer there (at the very least by the inverse square law of distance from the sun, if not also because of atmospheric conditions), so every single watt-hour those things can capture is critical.
Of course, to compensate for the thin film layers, they could have made the solar panels bigger - but that adds launch weight... not to mention the bigger solar panels would make the whole thing more top heavy and likely to tip over due to wind or ground obstructions, meaning you'd want to add size and wheelbase to this thing, meaning you'd need more solar panels... Do we see a vicious circle yet? [grin]
Fire and Meat. Yummy.
More useful, and what appears to have been implimented, would be a system where they can easily upload fixes/patches when un-expected errors appear.
I have to say though, despite being an extremely short video clip, it is one of the most awe inspiring things I've seen in a while. Think about it. We just viewed a sunset ON ANOTHER PLANET. I can just imagine an art gallery featuring nothing but pictures of sunsets on other planets. As much as I love our planet Earth, I hope the day comes when I'll be able to stand on Mars and watch this for myself. The beauty of the universe is infinite, but every now and then a little piece of that beauty finds its way back to Earth, and we experience this beauty, and smile a little, not quite realizing the magnitude of what has just occured.
Buy Steampunk Clothing Online!
Why did NASA stray from 'nuclear' batteries
Because the feel-good environmentalists have heart attacks when you mention the word nuclear. The risk is very low and the potential benefits to science are very high. The amount of nuclear material required is not large.
There are some problems with output from nuclear batteries, and I don't claim to be a rocket scientist - but surely it could be made to work.
I'll be laughing my ass off when oil triples in price and people are rioting - we'll see how long the nuclear boogeyman scares people then.
..don't panic
I would love to see notes from these kind of 'thought' groups. It is a big problem, and I think it should be put out into the public. Maybe a contest.
If you think the people t NASA can't figure it out, then nobody can, you are just kidding yourself.
The Kruger Dunning explains most post on
Of course, you are assuming all the dust has the same charge...
Not a likely situation.
'Sensible' is a curse word.
I dont buy this for a second. Removal of fine, electro-statically dust, has been practiced on this planet for centuries if not millenia. There are entire industries based on this practice. I am convinced that it was one of those famous NASA managerial pissing contests that ensured no "feasible" or "practical" solution. Read: the companies which proposed the solutions were not part of the "in" crowd.
This makes things sound worse than they actually are. They are not beginning to experience power supply problems -- they are simply getting less power than they were when it first landed, and they are taking some steps to operate more efficiently.
From SpaceFlightNow, in the report for THURSDAY, FEBRUARY 26, 2004 2215 GMT (5:15 p.m. EST):
From the Reuters report:
What the NASA official (Richard Cook) actually said was: "The vehicle is continuing to perform fine but we are starting to modify our daily process to respond to the decreasing power."
Both the dust accumulation and the decrease of sunlight were anticipated. The lifetime (designed to be 90 days) of each Rover is determined when the batteries can no longer be charged enough to survive the cold nights. Spirit is already 54 days into its 90-day "death sentence".
HCG 50a = 2MASX J11170638+5455016
11h17m06.4s +54d55m02s
I'm having trouble believing this picture... look how perfect it is! It's awe-inspiring that something like that truly exists
Berto
Every easy solution has a problem. The problem with this one is that the Mars rovers don't have any arms to rip the layers off.
[sarcasm]
You're right. I guess we will have to wait until someone invents robotic arms. And anything spring loaded wouldn't work because everyone knows springs don't work on Mars.
[/sarcasm]
There is nothing that can convince me that there is no way around this problem. It amazes me as much as the fact that NASA had prepared absolutely no way around losing a few tiles on the shuttle. These are major problems with simple solutions.
I think we have the wrong people running our space program.
"Nobody knows the age of the human race, but everybody agrees that it is old enough to know better." - Unknown
Not if the problem was well known beforehand as it was in this case. The dust was even experimentally observed on the Sojourner rover.
Why did NASA stray from 'nuclear' batteries, like they've used with the Pioneer, Galileo, Voyager and Cassini missions? Those could power a rover for years.
Most likely because the batteries would out-last the rover itself. It's a complex machine in a hostile environment- something will fairly soon. The solar panels will probably still be operating well after the rovers themselves have failed.
An interesting fact is that the cost of operating the entire mission is around US$ 3m a day, and that must also be considered when determining how long these wonderful bots rover through Mars unveiling its mysteries.
That is a good fact. But from my viewpoint the major cost has been the mission failures. All that money spent when a probe goes up in smoke is just completely gone with absolutely no return. It seems to me that 90% of the problem is getting the probe simply to have a successful landing. Since it is obviously so difficult and expensive, once that goal is accomplished the next priority should be robustness and longevity. Divide 3 million by the total cost of all rover failures and I think it would start to make more sense.
"Nobody knows the age of the human race, but everybody agrees that it is old enough to know better." - Unknown
This mission is a landing mission in the inner solar system, where the sun is bright enough to power the landers.
Second, the use of radioelectric power generators is risky, dangerous and expensive. If there's a less risky, less dangerous and less expensive option, NASA will gladly take it.
HCG 50a = 2MASX J11170638+5455016
11h17m06.4s +54d55m02s
The key difference you're missing is, in your own words, "on this planet". The fact that the rovers are on mars has two important effects. First, the atmospheric composition, weather conditions, and the nature of the martian dust itself render common dust abatement methods here on earth ineffective. The most common, spraying liquid and wiping, is totally out of the question when the temperature is -20 to -80 degrees C. Second, the inaccessability of a rover on mars means that complex mechanical "wiping" solutions are out of the question-- there's no one there to smack the side of the unit when a cam arm gets stuck, or replace a solar panel when a wiper blade gouges it with a sharp pebble.
If you're so sure there's an easy solution, let's hear it. Your bizarre conspiracy theory makes no sense.
If a job's not worth doing, it's not worth doing right.
They're so incredibly smart, in fact, that they don't even need to convert metric measurements to the archaic system they insist on using.
Don't knock US/SAE measurements, there's a good reason they've stayed around.
For scientific analysis, without question, Metric rules.
But when you're actually building and working on things, most of the time a 10% tolerance is good enough. As a result, usually you can stick your thumb across something and say, "Yup, that's an inch - close enough". The base units are more intuitive, although admittedly the interconversion between units is a bitch - but conversions are more common in analysis than construction/maintenance.
My perspective here? Canada went Metric in 1976. I grew up in Metric. I went to school in Metric, fuelled up my cars in Metric, got a set of Metric wrenches when I was a kid, etc. Heck, you wanna know Metric inside and out? Try taking an engineering degree in Canada!
And yet, I know I'm 6'4" tall, 185lbs. I don't know in Metric.
Every time I work on a car, I want to know first, Metric or SAE? (And I don't mean the speedometer, they've all been Metric in Canada since 1976.) Not because I care which wrenches, sockets and feeler gauges I bring, but because I like working on SAE much more.
Why?
I've had more cars with Metric fasteners and specs than I have SAE, and yet, somehow, I can still just put my thumb across a bolt and know, "Hey, that's not 1/2", that's 7/16"!" Why can't I do that with Metric? I sure which I could, especially since I've got more experience with Metric.
Fire and Meat. Yummy.
A lot of people are discussing ideas to remove dust from solar panels. Something people are forgetting is that there's a downside to having the mission last longer than originally expected: it costs more. JPL designed the rovers to last about 90 days, and NASA gave them enough money to pay the hundreds of engineers and scientists it takes to operate the rovers for 90 days each. They of course have the option of extending the mission for longer than 90 days, but the money to pay for that extension will come right out of NASA's Mars program, which means less money for future Mars missions (including Mars Reconaissance Orbiter 2005, which is already well under way and needs every penny it can get).
Does anybody have a link to Mars Rover science-in-progress? We are getting all sorts of operations/engineering reports and neat photos, but almost no science reports. What have the spectrometers found? Does the rock chemistry correspond to known minerals on earth or is it new? What ever happened with the briny mud speculations a few days back? I suppose there is a methodical plan to analyze and release papers, but it sure would be fun to at least know the basic composition of those sphericles for coffee break discussion.
"...while history is usually explicable it is often irrational" --Roger Spiller
Implement one of these in each fixed panel, not in the panels as a whole.
Another minor problem: this mechanism must be located the width of the panel away from the edge of the panel, i.e. any closer and it wouldn't be able to peel the layer off completely. Imagine, if you will, such a panel sitting before you with the film on it. Grab a corner of the film and attempt to remove it by pulling in a straight line, without letting go, and without moving your hand beyond the edge of the panel. See the problem? The panels, being the largest objects on the rover, would then require some sort of extended outrigger device beyond the panels to hold the reel that pulls the wire. Not an effective solution.
If a job's not worth doing, it's not worth doing right.