Mars Opportunity Rover Is In Danger of Dying From a Dust Storm (engadget.com) 105
According to NASA, the Mars Opportunity rover is currently trying to survive an intensifying dust storm on the red planet. "The storm's atmospheric opacity -- the veil of dust blowing around, which can blot out sunlight -- is now much worse than a 2007 storm that Opportunity weathered," reports NASA. "The previous storm had an opacity level, or tau, somewhere above 5.5; this new storm had an estimated tau of 10.8 as of Sunday morning." Engadget reports: The storm was first detected on Friday June 1st by the Mars Reconnaissance Orbiter, at which point the rover's team was notified because of the weather event's proximity to Opportunity. The rover uses solar panels, so a dust storm could have an extremely negative impact on Opportunity's power levels and its batteries. By Wednesday June 6th, Opportunity was in minimal operations mode because of sharply decreasing power levels. The brave little rover is continuing to weather the storm; it sent a transmission back to Earth Sunday morning, which is a good sign. It means there's still enough charge left in the batteries to communicate with home, despite the fact that the storm is continuing to worsen.
Obligatory XKCD (Score:5, Funny)
"The brave little rover": https://xkcd.com/695/
Re:Obligatory XKCD (Score:5, Funny)
That's Spirit.
You want: https://xkcd.com/1504/ [xkcd.com] for opportunity
Re:Obligatory XKCD (Score:5, Funny)
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I was thinking that NASA must be hiring writers who are roughly my daughter's age - when she was growing up, one of her favorite movies was "The Brave Little Toaster" [imdb.com].
Wait... (Score:2)
...how many stories have we read about dead rovers that miraculously come back to life after a mysterious "cleaning event"?
But here we are pronouncing the death of a rover due to a dust storm.
Re: Obligatory XKCD (Score:2)
When thinking about it - that little rover has far exceeded any expectations and done more for the exploration of Mars than most other missions so far.
How can we top this?
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Add some kind of wiper system to the panels to dust them off during these storms. Dust storms are common on Mars, why didn't they think of this when designing them?
On the contrary, the fact the rovers lasted as long as they did (Spirit)/ have (Opportunity) means that a wiper system would have been a poor design choice.
Re:Obligatory XKCD (Score:5, Interesting)
Others have supplied more uplifting endings to this strip:
https://i.imgur.com/VZvj5S7.jp... [imgur.com]
https://www.reddit.com/r/xkcd/... [reddit.com]
And my favourite:
https://imgur.com/VbKV9DF [imgur.com]
Re: (Score:2)
He'll be OK. Just art imitating life.
https://xkcd.com/1504/
Communicate With Home? (Score:3, Funny)
I wonder how long it could last in standby if someone hadn't been foolish enough to force it to waste power phoning home just to say "I'm still here." That single transmission could possibly be what killed it.
I'd also like to note that if Opportunity wasn't designed to power down safely (or recover to a working state if someone were foolish enough to not have it power down before completely running out of power) recharge the batteries when there's enough sunlight, then have Opportunity restart, someone needs to loose their engineering degree.
Re: Communicate With Home? (Score:5, Informative)
The more pressing problem isn't that it can't reboot, it's that it won't be able to clean its panels after the storm, and that's assuming it can even do that. Not to mention the drop in efficiency from getting the panels scarred up by abrasive dust.
Godspeed little rover, keep up the fight!
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I'm sure one of the dust devils will come along and clean the panels.
Windy [Re: Communicate With Home?] (Score:2)
I'm sure one of the dust devils will come along and clean the panels.
This location, on the rim of Endeavour crater, has been pretty windy. So if the rover calls home after the dust storm, there's a pretty good chance that the winds will clean the panels.
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This isn't the first time we've heard that it won't be able to clean it's solar panels after the dust storm.
What happen all the previous times was that the storm blew the dust away from the solar panels, so they ended up cleaner after the storm.
Re:I came here to read this. :) (Score:5, Insightful)
You know how I can tell that neither of you actually read the article?
The main concern here isn't the dust storm itself. It's the need to keep the rover's heaters operational while maintaining a minimal power level in the batteries.
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It doesn't have any system to clear its panels (Score:5, Insightful)
Opportunity and Spirit are not fitted with any mechanism to clear their solar panels. Originally, it was assumed that dust on the panels would be what would end the mission. But winds and whirlwinds were found on the planet, these occasionally blew dust from the panels, and the mission was extended.
The pressing problem is that there won't be enough energy to keep the heaters running, the electronics will cool down to -50C, and either the heaters won't turn back on when the sun returns, or, if they do, the electronics won't work when they defrost.
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IIRC, the temperature concern isn't just about the electronics - it's also the cameras. The glass in the lenses has a lower coefficient of expansion than the metal rings they're mounted in. This means the metal shrinks faster, and may crack the lenses even a
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It's discussed in Roving Mars by Stephen Squyres. (You might have heard of him - he's the PI for the MER program.)
They're absolutely worried about absolute temperatures - because those temps affect the current draw of the heaters.
Re: Communicate With Home? (Score:5, Informative)
At the moment the problem is not how much dust will be on the solar panels after the storm. It is that it will lose all power during the storm, the heaters will stop working, and will then be unable to reactivate afterward.
The story reports an optical depth of the dust storm of tau=10.8. This is astoundingly dark. The transmittance of light through the atmosphere is 1/e^tau so that only 1/50,000 (0.002%) of the sunlight is getting through! It is effectively perpetual night there right now. This is probably darker than even the heaviest storm clouds on Earth (which only go up to blocking 1/20,000 of the sun light). Thus far the storm has cut off power for six days.
Although the storm also moderates temperature, since it prevents radiation cooling at night, it also means that the day time high temperatures are not reached either, so that the heaters have to be cranked up constantly (though not to the level of coldest night chill), with no power replacing what is being drained from the batteries.
It the batteries drain to the level that they can no longer supply the heaters then whether there is dust on the panels after the storm ends will be moot. Opportunity will be dead.
Tau [Re: Communicate With Home?] (Score:3)
...The story reports an optical depth of the dust storm of tau=10.8. This is astoundingly dark. The transmittance of light through the atmosphere is 1/e^tau so that only 1/50,000 (0.002%) of the sunlight is getting through! It is effectively perpetual night there right now....
Note that the e^1/tau factor is for direct beam. What this means is that almost all of the light that gets through to the surface is scattered light.
The tau for a rainy day for earth is very high too. It doesn't mean that the surface is completely dark, it just means that the light that does get through has scattered many times-- you can't see the disk of the sun, but some light does reach the surface.
10.8 is a record for the highest tau measured from the surface of Mars, though.
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The analogy I've been using is of being under a volcanic ash cloud. Literally turning day into night.
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I'm surprised that they didn't engineer some way to at least superficially clean the panels. The panels are hinged and they were folded in transit. Obviously something so delicate wasn't spring loaded to smack open. Could they really not reprogram the servos to have the panels tilt up and down to let the sand fall off?
Dust sticks electrostatically. I think the panels are fixed, but the rover can tilt. Unfortunately you really you can't shake it enough to overcome the electrostatic attraction of the dust.
To actually clean the panel (rather than just leave it to occasional opportunistic car washes by martian dust-storms) the only ways appear to be: to actually smack it (vibrate it) enough to overcome the electrostatic dust attraction OR use some sort of electric field to manipulate the dust.
https://www.technologyreview.c [technologyreview.com]
Re: Communicate With Home? (Score:5, Informative)
It needs battery to keep the internal components at safe temperature levels. It is not about calling home; it is about not freezing.
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The funny thing is going to be when that storm clears the panels on Spirit enough that it starts phoning home again. :-)
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I wonder how long it could last in standby if someone hadn't been foolish enough to force it to waste power phoning home just to say "I'm still here." That single transmission could possibly be what killed it.
Um, no.
Re:Communicate With Home? (Score:5, Informative)
...someone needs to loose their engineering degree.
Someone needs to remember this hardware was originally expected to last 90 days. It's been running for over fourteen fucking years.
This would probably be one of those times where you should STFU about failures in engineering and design, as the statistics tend to speak for themselves.
Re:Communicate With Home? (Score:5, Funny)
That's 14 earth years, not 14 fucking years.
That being said, I didn't know that fucking was a planet, we should let more people know, it would really help build interest in space exploration.
Re:Communicate With Home? (Score:5, Interesting)
On one hand, I think those engineers need a discussion about underestimating capabilities.
On the other, I think they need to be given god damm medals for making a project beat its lifespan estimates, not by 10%, not by 100%, not by 1000%, but by 5500%.
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Someone needs to remember this hardware was originally expected to last 90 days. It's been running for over fourteen fucking years.
This would probably be one of those times where you should STFU about failures in engineering and design, as the statistics tend to speak for themselves.
As a mass-production engineer I would be asking serious questions about the design process and quality controls.
Having a product last for over 56x longer than its designed and projected lifespan suggests that there is some serious over engineering involved. Are all those solar panels really needed? What if we added some lightening holes to the neck, the solid piece of aluminum seems like overkill and the weight savings will help lower distribution costs.
Honestly though, how can anyone pass judgment on t
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The Internet: passing judgement on others without all the facts is kind of our thing
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But the charges for return shipping, or sending out a field tech, would be a real bitch.
The acceptable risk of failure was a bit lower for this hardware. You wouldn't want to be that guy [space.com].
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You must work for a smartphone manufacturer. Please quit your job and let me decide when to retire my electronics.
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Of course there is some serious over engineering involved. The design process and quality controls could likely be summed up as "It just has to work",regardless of the mission's expected duration. There is just too much at stake to even care about minimizing materials beyond the defined mission requirements.
90 days is likely to be the warrantee period for a cheap motherboard. If you think getting an RMA for one of those is a pain, try getting an RMA for a product delivered to MARS.
re: designed to last 90 days (Score:5, Informative)
Seriously, you have to take those claims of "designed for 90 days of operation" with some big grains of salt.... There's no way they'd spend all the money, time and energy on R&D to get something like this put on Mars, when they REALLY only expected it would be used for a few months.
That might be the length of time they NEEDED to complete the original planned research project, so in a worst-case scenario, NASA doesn't have to say they failed. But I'm quite certain this thing was engineered with the hopes it would run for years and years -- as it has done.
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Seriously, you have to take those claims of "designed for 90 days of operation" with some big grains of salt....
Good point. I didn't see the project requirements. My guess is the actual requirement was something like "99% chance of operating for at least 90 days." It wasn't "10% chance of operating 90 days." That's a pretty big difference. I might be able to build the latter. I have no chance on the former.
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There's no way they'd spend all the money, time and energy on R&D to get something like this put on Mars, when they REALLY only expected it would be used for a few months.
Why not? The first month of operation was likely the most insightful and it did most everything it was going to do and flexed all of it's scientific equipment. It got pictures, dug a trench, analyzed the air, and did spectrometry. It also traveled to a location with hematite, which geologists were eager to study. That's all in month 1.
Given a set of tools, there's only so much science you can do. Rovers can move around and use the same tools and more locations, which is awesome, but eventually there w
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If you think they didn't think of that, then *you* should lose yours.
Re:Communicate With Home? (Score:5, Informative)
someone needs to loose their engineering degree.
I don't know about that but somebody definitely needs to learn to spell "lose".
It's only four letters, FFS.
Tau (Score:5, Informative)
Since this article doesn't explain it, an optical depth tau value of 10.8 means approximately 0.002% of the sunlight is reaching the rover, compared to 0.4% for the last storm. It's really, really dark out there.
OK - so the darkness isn't really relevant. (Score:5, Informative)
0.4% of the sunlight wouldn't have be enough to make the solar panels work. So a greater darkness than that doesn't really make any difference. It might as well be pitch black if the intensity is below 1%.
What is important, then, is how long this dust storm will last.
Moonlight is nice, but not bright (Score:2)
My solar panels generate power under a full moon. Every little bit helps.
Enough to detect, maybe.
Enough to charge a battery, no.
The full moon isn't bright enough. The full moon gives 400,000 times less light than the sun.
next time they build a rover for mars (Score:2)
Re: next time they build a rover for mars (Score:1)
Or maybe they should build the next rover so it doesn't need solar panels. Maybe use a nuclear power source like an RTG. How cool would that be? They could name it Curiosity.
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they should build it to look like a GIANT beetle, and build the solar panels like the wings that can fold out when the conditions are good and when not so good fold in and collapse flat with a hard weather-proof outer shell that covers and protects them (like some beetles that can fly)
That is not a bad description of the Soviet Lunakhod rover design, which enclosed the array at night.. Although most people say that they look more like a giant bathtub than a beetle.
climate change! (Score:3)
"The storm's atmospheric opacity -- the veil of dust blowing around, which can blot out sunlight -- is now much worse than a 2007 storm that Opportunity weathered," reports NASA.
The storms are getting worse ... what do you Martian "deniers" say now, eh???
Job well done and then some... (Score:4, Informative)
Re:Job well done and then some... (Score:5, Informative)
The decay of Pu-238 will not be what limits the Curiosity mission. It has a half-life of 87.7 years. The RTG that uses that decay to produce electricity (and, perhaps more importantly at the moment, heat to keep the electronics happy) decays more quickly than that. But the Voyager probes still have enough electricity to communicate with earth forty years after launch.
The limiting factor for Curiosity will probably be its moving parts. Specifically, its drive motors and wheels. The wheels have taken quite a beating [google.com], and may eventually be so damaged that they can no longer provide adequate traction. The JPL guys are really clever, and can probably drive Curiosity even with the complete loss of one wheel.
But even if Curiosity stopped moving tomorrow, it would almost certainly still be useful for stationary science. It can continue to gather weather data (including measuring atmospheric methane, which hit the news recently), take pictures, shoot lasers, and sample rocks, probably for years. One of the Viking landers lasted 6 years on the surface, and that mission ended only after a bad software update [wikipedia.org].
Re:Job well done and then some... (Score:4, Interesting)
Solar panels definitely also decay over time, but those on the Mars Pathfinder mission saw a long term degradation of only about 0.15% per (earth) year. Their decay doesn't also require more energy to be used for heating due to less waste heat being produced.
I'm probably worrying too much and the thing that kills Curiosity probably is the environment with the way the soil is rich in really corrosive substances like perchlorate.
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And the goal is to simply not power everything at once. There's a minimum amount of power it needs to run the basics, yes, and that minimum is probably served by the RTG for decades
All the power hungry science packages can simply be turned off when they're not needed or used, conserving available power as it deca
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Not true. Loss of power generating capacity is already limiting what the Voyager probes can accomplish - and they're only 41 years old. Whil
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wall flower culture shock (Score:2)
I think you're abusing the word "expected".
There was a high-likelihood failure mode (involving dust accumulation) which was baked into the mission parameters, whose budgetary concerns centered around achieving a minimum sufficient return on investment (the worst outcome of all in space exploration is no learning).
But if you'd asked anyone involved with a clue, they'd have said that the uncertainty around the dust accumulation model was high, and th
Not necessarily (Score:2)
If I remember correctly, one such sandstorm also _cleaned_ the solar panels in the past.
Didn't I just see this? (Score:2)
There was a book or movie about this. We need to ship Opportunity some potatoes and duct tape, something like that.
Easy to solve (Score:1)
If NASA was like really smart,they could have equipped the rover with flashlights that would shine on the solar panels when the sun is obscured by a dust storm. Problem solved! But noooo, NASA is of course full of liberal elitists who just use equations to explain why something cannot get done!
The little rover that could (Score:2)
15 YEARS into its 90 DAY mission.
IthinkitcanIthinkitcanIthinkitcan.