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Mars Rovers Update

michael posted more than 10 years ago | from the never-will-play-the-wild-rover-no-more dept.

Space 320

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."

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fuck her in the ass (-1, Offtopic)

Anonymous Coward | more than 10 years ago | (#8418544)

hell yeah [netfirms.com]

Hey, where are the conspirency theorists... (0, Offtopic)

imsabbel (611519) | more than 10 years ago | (#8418547)

Was the sunset REALLY blue?

Gentoo? (0, Funny)

Anonymous Coward | more than 10 years ago | (#8418548)

I use Gentoo; how does this affect me??

Planning Ahead (1, Interesting)

Piethon (748147) | more than 10 years ago | (#8418549)

Maybe it would be better if we tested the software more on earth and had all the bugs worked out before we sent it up. It seems like all of these problems could have been avoided if we would have just uploaded the software BEFORE we launched them and had thorough testing. If NASA would do things other than try to get pretty pictures to increase its funding, maybe something more might come out of it.

Re:Planning Ahead (5, Insightful)

toast0 (63707) | more than 10 years ago | (#8418860)

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.

Re:Planning Ahead (2, Insightful)

jeff munkyfaces (643988) | more than 10 years ago | (#8418912)

i'm sure they thought they had ironed out all bugs.

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.

Battery problems... (-1, Offtopic)

Bryan Gividen (739949) | more than 10 years ago | (#8418550)

Had a friend switch from XP to Linux on his laptop and it double his battery life... change to Linux maybe?

Solar problems (5, Interesting)

LotsaCaffeine (312054) | more than 10 years ago | (#8418556)

NASA should have installed wiper blades on the solar panels.

Re:Solar problems (2, Interesting)

MikeCapone (693319) | more than 10 years ago | (#8418572)

NASA should have installed wiper blades on the solar panels.

I know you are joking, but I'm actually surprised that they haven't thought of a way to keep the solar panels clean.

I mean, they can get the thing to mars, they should be able to do that, no?

Re:Solar problems (3, Informative)

r00zky (622648) | more than 10 years ago | (#8418592)

For an easy solution see: helmets of Formula One drivers.

Re:Solar problems (4, Insightful)

Anonymous Coward | more than 10 years ago | (#8418606)

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.

Re:Solar problems (3, Interesting)

r00zky (622648) | more than 10 years ago | (#8418662)

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.

Re:Solar problems (4, Insightful)

Anonymous Coward | more than 10 years ago | (#8418714)

If only life were so simple, you'd be working for NASA...

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?

Re:Solar problems (5, Informative)

Anonymous Coward | more than 10 years ago | (#8418852)

How is the motor supposed to pull the correct wire (you wouldn't use thread)? Ten different motors?
A simple set of 10 mechanical gears made of plastic and stacked in a row would do this. The driving gear jumps from first to last as needed. My printer does something similar to this everyday to a precission of 720 dpi so...

What do you do with the tear-off once you pull it?
Cut the wire between the plastic sheet and the gears that rolled the wire. No need to have 10 cutting devices, since only one wire will get rolled at a time.

Don't forget that you have to pack all of this onto the rover and fold up the panels.
Implement one of these in each fixed panel, not in the panels as a whole.

All of this stuff takes up weight and adds complexity
Sending 2 probes to Mars and getting scientific data back is waaaaay more complex than this. And the weight... it adds a little more $$ for fuel, but the result is a _much_ longer lifetime.

Re:Solar problems (0)

Anonymous Coward | more than 10 years ago | (#8418908)

The cost of the extra fuel is utterly irrelevent for a mission like this. It's the *weight* of the extra fuel that is the problem. Additional weight (and complexity) on the rover requires extra fuel. The weight of that fuel requires even more fuel to lift it, which in turn requires more fuel .... ad infinitum. Of course, the increase in fuel each time is of a diminishing amount so there is a limit. Weight is however the number one problem to overcome when designing aerospace vehicles.

Re:Solar problems (0)

Anonymous Coward | more than 10 years ago | (#8418936)

Well... that must be one reason why i don't work in the NASA :) the other being that i'm not in the mood of going to the USofA anytime soon, not even payed.

Re:Solar problems (-1, Flamebait)

Anonymous Coward | more than 10 years ago | (#8418983)

the other being that i'm not in the mood of going to the USofA anytime soon, not even payed.

WHAT?! But everyone wants to come to the good 'ole US of A! It's the best country on earth! You must be absolutely nuts if you want to stay in that shithole country of yours!

Re:Solar problems (0)

Anonymous Coward | more than 10 years ago | (#8418887)

Going to need ten pyros for that.
Forgot to say: no need to put the rover in fire, a tiny mechanical dented-guillotine device should have no problem cutting a wire similar to that used for fishing.

Re:Solar problems (0)

Anonymous Coward | more than 10 years ago | (#8418752)

I wonder if NASA considered parent's idea. If not, parent post is great argument for running the next generation of probes sent (somewhere) past an open discussion forum.BR.or do they alredy do that?

agreed (5, Funny)

SweetAndSourJesus (555410) | more than 10 years ago | (#8418861)

I'm sure a bunch of half-baked ideas from random yahoos would get them much further than anything their silly engineers could come up with.

Re:agreed (2, Interesting)

IgnoramusMaximus (692000) | more than 10 years ago | (#8418898)

That is not the point. If a bunch of random yahoos can come up with, on the face of it, at least partially feasible ideas and the engineers in charge dont do anything about it including providing explanation as to why they ignored the issue, you got an impression of incompetence or some hidden agendas.

Re:agreed (2, Interesting)

Anonymous Coward | more than 10 years ago | (#8418933)

you got an impression of incompetence or some hidden agendas.

At least you have an appropriate nickname. There are many cool features that NASA engineers would like to have included on the rovers. But at some point, decisions have to be taken on what things will not fly. These decisions are based on many criteria including weight, complexity, cost, etc. There is no hidden agenda here and the missions have been a great testament to the competence of NASA engineers.

Re:agreed (-1, Flamebait)

Anonymous Coward | more than 10 years ago | (#8418946)

and the missions have been a great testament to the competence of NASA engineers

Especially when you consider how many of them failed. NASA is just another fucking company which will hire anyone who can show a degree from the right university, no matter how incompetent he or she may be. Stop thinking that NASA is different in that aspect.

Re:agreed (0)

Anonymous Coward | more than 10 years ago | (#8418937)

Coming up with a solution to the problem "dust accumulates on the solar panels" is not the difficult part. Every idiot engineering student or even lower lifeforms could do that.

The difficult part is thinking of it beforehand.

Layers on Panels are a Bad Idea (4, Insightful)

BigBlockMopar (191202) | more than 10 years ago | (#8418884)


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]

Re:Layers on Panels are a Bad Idea (-1, Flamebait)

Anonymous Coward | more than 10 years ago | (#8418926)

I like the way how you try to appear intelligent and how you capitalize "bad idea" to show what an eleet hax0r you are.

Re:Solar problems (3, Interesting)

IgnoramusMaximus (692000) | more than 10 years ago | (#8418687)

You are kidding for sure.

Say, a step motor and some mechanical jiggery-pokery ending with a stiff wire, a hook on its end, the layers would have tabs with holes in them to pull at.

Or.. a glue between layers that deteriorates on contact with Martian athmosphere and so the layers will peel off after a fixed (based on chemistry) time.

I mean, give me a break, those took less then 10 seconds to come up with and I am sure NASA engineers could have thought up much more effective methods.

Re:Solar problems (3, Interesting)

torpor (458) | more than 10 years ago | (#8418823)

Put the solar array on a vibrator, tilt the rover slightly, and give the solar panel array 15 minutes of shaking at some appropriate Hertz... oila, dust is shaken off.

Re:Solar problems (5, Interesting)

IgnoramusMaximus (692000) | more than 10 years ago | (#8418856)

A vibrator? Might work although probably could be destructive...

Hmm, after another 15 minutes of mental effort: a thin brush on an arm mounted to the side of the camera mast. You lower the (very thin and light single file brush) with a small step motor to the horizontal position and then you rotate the camera mast to create a sweeping motion on the panels. You could brush the 2 side panels that way, since if you planned for it, there would be no portruding gear to get in the way of the brush (all such gear would be back of the mast).

And so on...

I am really flabbergasted why there is absolutely no provision for any sort of cleaning (even a partial one) on the rovers. Its not like this wasnt expected. I smell some sort of hidden agenda in shortening the life of the rovers.

Re:Solar problems (0)

Anonymous Coward | more than 10 years ago | (#8418610)

And just who is going to pull off the tear-off? The Martian pushing the rover along?

Yet another stupid idea from another wannabe engineer.

Re:Solar problems (5, Interesting)

ModernViking (244510) | more than 10 years ago | (#8418755)

First, my credentials. I have worked on the field trials of the FIDO rover. It is the science test bed for the MER rovers that has been tested in various parts of the western United States over the past 6 years.

There have been many ideas tested for the solar panels, including removable plastic coverings, wiper blades, etc. None of them have proven practical. The dust on Mars is extremely fine and electrostatically charged. It sticks to the panels , and every other surface, amazingly well. Figuring out a way to remove Martian dust from surfaces is a field that a lot of thought and experiment has gone into, without discovering any feasible solutions, so far.

During the Pathfinder Mission in 1997, it was found that, by driving the rover over 'large' rocks (large for the rover), some of the larger dust can be shaken off. This is, as I've heard from members of the engineering team, something they intend to try with the MER rovers when needed. It doesn't make a huge improvement, on the order of a couple percent, but every little bit helps.

Re:Solar problems (3, Insightful)

Flakeloaf (321975) | more than 10 years ago | (#8418821)

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?

Re:Solar problems (3, Insightful)

Daniel_Staal (609844) | more than 10 years ago | (#8418968)

Of course, you are assuming all the dust has the same charge...

Not a likely situation.

Look harder! (4, Funny)

Serious Simon (701084) | more than 10 years ago | (#8418864)

Once the robots find water, they could spray it on the solar panels to clean the dust off...

Re:Solar problems (3, Interesting)

deglr6328 (150198) | more than 10 years ago | (#8418889)

Can you say more about why specifically the peel off transparent plastic idea was rejected(it seems to be the simplest, most effective, non-single point failure prone, most elegant solution I've seen so far)? I know all these speculative posts seem tedious and redundant, it's just that it seems like such a shame to allow the mission life of the rovers to be so severly shortened by such an apparently trivial problem.(it's just a little dust!! :o)

Re:Solar problems (1)

taion (304184) | more than 10 years ago | (#8418952)

The dust is electrostatically charged, so simply detaching the plastic layers wouldn't be sufficient, as they'd still be stuck onto the panels. You'd need some way to do more than just cut off the layer.

Additionally, even transparent plastic would reduce the amount of light striking the panels by some amount. Multiply that by however many layers you want, and the effect likely becomes significant.

Re:Solar problems (2, Funny)

jeff munkyfaces (643988) | more than 10 years ago | (#8418925)

would it be possible to set them into "violent shaking mode" to solve this?

Re:Solar problems (2, Insightful)

geekoid (135745) | more than 10 years ago | (#8418940)

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.

Answering myself (1)

MikeCapone (693319) | more than 10 years ago | (#8418877)

I'm by no means an engineer, but I'll try to answer myself. Feel free to point out what I got wrong.

Couldn't they have many transparent protective layers on top the solar panels, so that once the top one becomes dirty it is ejected/separated from the panel (with the dirt)?

Re:Solar problems (0)

Anonymous Coward | more than 10 years ago | (#8418892)

I know you are joking, but I'm actually surprised that they haven't thought of a way to keep the solar panels clean.

I mean, they can get the thing to mars, they should be able to do that, no?


Ummm, no... We're talking about Americans here afterall...

Re:Solar problems (4, Interesting)

hottoh (540941) | more than 10 years ago | (#8418709)

I understood Nasa to say 'wiper blades' would not be effective due to the nature of the fine dust chemically sticking to the surface of the solar cells. Mechanical sweeping does not solve the real problem of the dust sticking to the solar panel.

Just a guess based on Nasa commentary is the batteries will fail before the solar panels fail to charge them.

Re:Solar problems (1, Troll)

nomel (244635) | more than 10 years ago | (#8418751)

but then the rovers might last forever, and they wouldn't as easily get funding for new projects.

if you think about it, the reason has to be some conspiracy like this...seriously.
We got the thing to the moon, but we can't keep dust off the solar panels...come on!

Re:Solar problems (4, Funny)

Bull999999 (652264) | more than 10 years ago | (#8418801)

Another problem with rovers lasting forever is that they may gain AI, build themselves up with other technology, and go on a killing spree until a witty captain of a spaceship stops it.

The question is.. (-1, Offtopic)

Anonymous Coward | more than 10 years ago | (#8418568)

..is that a blue sun set, or the work of adobe photoshop's ol` shadow settings + white circle trick?

ACPI (4, Funny)

compbrain (625174) | more than 10 years ago | (#8418571)

"The hack works by reducing the power supply to a poorly functioning switch."
You know, they could just tell the rover to use its ACPI functionality and go into standby and spin down its hard disks....

Re:ACPI (1, Funny)

Anonymous Coward | more than 10 years ago | (#8418589)

that doesn't even make sense. stop trying to sound smart.

Re:ACPI (0)

Anonymous Coward | more than 10 years ago | (#8418623)

Way to rain on his parade.

Re:ACPI (1)

Zaiff Urgulbunger (591514) | more than 10 years ago | (#8418809)

Do the rovers have hard disks? I've not heard any mention of disks during any tech. reports... only volatile and flash memory.

Re:ACPI (2, Funny)

dzym (544085) | more than 10 years ago | (#8418753)

Except ACPI doesn't work properly on anything but Windows.

Nice try.

Re:ACPI (0)

Anonymous Coward | more than 10 years ago | (#8418783)

Doesn't the rover use linux? :P

Fan (4, Interesting)

RetroGeek (206522) | more than 10 years ago | (#8418578)

Is there some reason why these rovers do not have a fan to blow away the accumutating dust on the solar panels?

The weight penalty should be offset by being able to work longer.

Or is the dust sticky? Maybe something akin to a wiper?

Was panel was sticky ? (1, Funny)

dapyx (665882) | more than 10 years ago | (#8418609)

Or is the dust sticky?

Actually it was revealed that the panel was sticky. The NASA engineers don't want to discuss about the source of stickiness.

Re:Fan (-1)

Piethon (748147) | more than 10 years ago | (#8418617)

Maybe because there isn't enough air on mars to be blown? (E.G. Any at all)

Re:Fan (3, Interesting)

goon america (536413) | more than 10 years ago | (#8418647)

Doesn't one of their robot arms have a brush device for brushing off rocks? Couldn't they use that?

Re:Fan (5, Informative)

RetroGeek (206522) | more than 10 years ago | (#8418659)

Doesn't one of their robot arms have a brush device for brushing off rocks?

The ONE robot arm cannot articulate to a position to reach the panels (it is mounted underneath). Also, the brush is made of wire. Not something you would want rubbing against a solar panel.

Re:Fan (0)

Anonymous Coward | more than 10 years ago | (#8418759)

You know I read this and was thinking about that little itch right in the hard-to-get-to place in the middle of my back and I thought ... backscratcher. You could just put a little wiper blade on a stick and, viola, instant solar panel backscratcher!

Re:Fan (0, Redundant)

Anonymous Coward | more than 10 years ago | (#8418812)

The brush is also made of metal.

Wiping the dust off of high-end solar panels with a wire brush is really not a very good idea at all.

Re:Fan (1, Insightful)

deglr6328 (150198) | more than 10 years ago | (#8418675)

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 [tps-online.com] 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.

Java problems? (-1)

dapyx (665882) | more than 10 years ago | (#8418582)

engineers will upload a software hack to decrease the recent power drain plaguing the rover Opportunity. The problem was probably caused by some incompatibility in the Java system. :-) Thank God they're not using Visual Basic.

Re:Java problems? (5, Informative)

Anonymous Coward | more than 10 years ago | (#8418603)

The problem was probably caused by some incompatibility in the Java system

Repeat after me.

There is NO Java on the rovers. Java is used on the ground to process the results.

Idiot. Enough has been posted on this site about where Java is being used.

Re:Java problems? (2, Informative)

mrtom852 (754157) | more than 10 years ago | (#8418811)

Some important (I presume) Sun person made the Java on Mars claim at a recent Sun Tech Day. She was quickly corrected by another (more important) Sun guy but it's easy to see how people are getting confused if some Sun sales people are spreading this rubbish.

Re:Java problems? (4, Interesting)

KewlPC (245768) | more than 10 years ago | (#8418627)

Java is only used on the ground. They'd be stupid to use it in the flight software.

That isn't a slight against Java. It's just that they need real-time software, which can't be had with an interpreted language (even if it is only interpreted from bytecode).

How fast do you think a 20mhz processor could run a Java app?

Re:Java problems? (1)

mcbridematt (544099) | more than 10 years ago | (#8418731)


How fast do you think a 20mhz processor could run a Java app?

Very Slowly. Keep in mind there are native Java Bytecode CPU's out there, but who uses them? My guess is nobody :(.

But at least no more memory problems with Java ;-) (0)

Anonymous Coward | more than 10 years ago | (#8418872)

Just joking. Java prevents application memory problems by making them all VM memory problems.

Re:Java problems? (2, Interesting)

r.jimenezz (737542) | more than 10 years ago | (#8418959)

I think the main issue with Java is not the processor, but several other qualities that, while highly desirable for a general purpose language, are unacceptable for real-time systems (garbage collection is one of them).

This is why there's been work for a real-time version of Java for a number of years now (see here [rtj.org] ). Incidentally this is what kicked of the JCP (it's JSR-001 :)), and according to my Concurrent and Realtime Programming in Java lecturer (Andy Wellings [york.ac.uk] , who sits in the Technical Interpretation Committee for this JSR), NASA is quite interested in this as an option for its future missions to Mars.

Re:Java problems? (5, Informative)

nehril (115874) | more than 10 years ago | (#8418990)

this is slightly OT, but "real-time" in engineering circles does not mean "really fast." it means that there is a guaranteed response from the system within an specified actual time frame.

i.e. I need a real-time OS & software stack if my rocket control algorithm needs the data from, say, a serial port altimiter within the next 20 milliseconds or else. if you cant get the data within the specified timeframe then the results are useless. the system will not accept requests that it cannot "guarantee" to fulfil from a system resource standpoint. (you have to watch your multitasking, swapping and other kernel-level tasks to achieve this)

so you could have a 20 mhz "real-time" system, as long as it's response was guaranteed by the OS within parameters for what you are doing (and you would program with those guaranteed response times in mind.) Conversely, a 20 Ghz system may not qualify for real time, if the OS pre-empts your rocket control task and decides to swap for a few milliseconds too long, or context switches to another thread just when you needed to adjust a control surface...

when you hear about people hacking linux for real-time work, they are not making it go faster (though that's always nice), they're making it work predictable.

What no Roomba? (1, Troll)

rodney dill (631059) | more than 10 years ago | (#8418591)

You would think they would have installed some mechanism to clean the dust off.

software problems with the rovers (-1, Troll)

Anonymous Coward | more than 10 years ago | (#8418607)

You know, I cannot help but think that the fact that VxWorks is written in Java is a major contributing factor to both rover's software issues.

I'm a project manager, and I've worked with a lot of development teams on many different projects. Generally speaking, I have found Java based applications to be poorly designed, and therefore poor performing.

With .NET projects, however, development not only goes faster, but the resulting code tends to be much more stable.

I'm not certain if this is because .NET seems to attract better talent, or if it is just because .NET is the superior platform.

Just one manager's opinion.

Difficulties in planning space missions (4, Insightful)

nicnak (727633) | more than 10 years ago | (#8418611)

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.

Re:Difficulties in planning space missions (4, Informative)

Gossy (130782) | more than 10 years ago | (#8418721)

Um, I seem to recall they knew about dust problems well before they launched. This isn't something that has surprised the engineers. I remember that was the main reason they said they were planning for a 90 day mission, since beyond that point the cells wouldn't charge enough due to the dust.

I've also seen on SpaceFlight Now reports that projections show they will be probably be able to run both rovers well beyond the initially planned 90 days, so they're looking into plans for extended missions now.

However, like others on the thread have wondered, why not devise something to remove the dust? I'm sure there must be a good reason why they didn't do something - I can't imagine the NASA engineers simply didn't think about this.

Re:Difficulties in planning space missions (2, Funny)

stonebeat.org (562495) | more than 10 years ago | (#8418735)

if we send men to Mars, hopefully they are wise enuff to get out of the rover (in space suits) and clean the solar panels. ;)

Re:Difficulties in planning space missions (2, Insightful)

BeerCat (685972) | more than 10 years ago | (#8418765)

Until we do this a few more times and figure out a few more things, a manned mission will have to wait.

Excpet that with a manned misison, a quick way to wipe the solar panels would have been worked out at least as fast as the recent /. posts.
The more remote missions there are, the more the "just one more remote mission" feeling will accrue. If Apollo 11 had been a remote mission, the Eagle would have crashed, because of a rock in the (automated) landing zone. As it was, Armstrong did a quick manual burn to hop over the bad area, and landed safely (with fuel reserves probably below what an automated system would have worked well with)
Therefore, while the experience gained from a remote mission is valualble, it is no replcament for "hands on"

NASA (-1, Offtopic)

Anonymous Coward | more than 10 years ago | (#8418622)

Are a bunch of newbs! OMG LOL!!!!!11

Blue Skies on Mars??? (1, Funny)

vudufixit (581911) | more than 10 years ago | (#8418629)

Is this before or after the NASA guys visited the Rekall Corporation?

This just in from Saturn (5, Interesting)

blamanj (253811) | more than 10 years ago | (#8418632)

A nice photo [nasa.gov] from the Cassini mission.

Re:This just in from Saturn (-1, Offtopic)

Anonymous Coward | more than 10 years ago | (#8418668)

What idiot modded the parent off-topic?!

Re:This just in from Saturn (-1, Flamebait)

Anonymous Coward | more than 10 years ago | (#8418696)

Mars vs Saturn maybe?

Re:This just in from Saturn (5, Informative)

deglr6328 (150198) | more than 10 years ago | (#8418747)

Don't mod the above off-topic, it's still about space! I submitted this story yesterday and it was rejected :( so here is probably the only place you're going to see it and it's really interesting imho! Cassini is entering the final phase of its 7 year journey to saturn and starting now will be sending back images and other measurements at a "rapid and steady pace [arizona.edu] ". In a few months Cassini will enter orbit around Saturn after performing what should be a spectacular ring plane crossing [nasa.gov] .

Seasonal changes (5, Interesting)

Dan East (318230) | more than 10 years ago | (#8418639)

The blurb fails to mention that seasonal changes on mars are resulting in less sunlight per sol. That is one of the main power issues.

Dan East

Re:Seasonal changes (1)

RetroGeek (206522) | more than 10 years ago | (#8418678)

From the "blurb":

the approach of autumn on the Red Planet

shorter periods of sunlight

Re:Seasonal changes (4, Insightful)

Dan East (318230) | more than 10 years ago | (#8418706)

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

Re:Seasonal changes (0)

Anonymous Coward | more than 10 years ago | (#8418780)

RTFA

We can put 2 rovers on Mars... (0, Informative)

Anonymous Coward | more than 10 years ago | (#8418698)

...and fix software problems they're having from a control room on Earth, but we can't figure out how to build the equivalent of a windshield wiper to gently clean the dust off the solar panels?

As nice as it would be... (3, Informative)

r.jimenezz (737542) | more than 10 years ago | (#8418768)

...to have the dust wiped off the rover's solar panels, it has many disadvantages. It has been discussed widely here, even by rocket scientists. In short, it is extremely difficult to come up with a "cost-effective" (from several viewpoints) mechanism. 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.

Dust on solar panels issue (4, Insightful)

thedillybar (677116) | more than 10 years ago | (#8418770)

Every "feature" you add to this thing has its tradeoffs.

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...

Re:Dust on solar panels issue (1)

XaosTX (723612) | more than 10 years ago | (#8418930)

You forget that you are on Slashdot. We like to complain that someone else isn't as smart as we are.

The Martian Dust (5, Interesting)

Chris Tucker (302549) | more than 10 years ago | (#8418791)

The big problem is that the dust is so fine, it'd be very difficult to wipe it off with anything akin to a windshield wiper. You might remove the dust, but the grit would scratch the glass, eventually causing enough opacity that the panels would eventually be rendered useless.

One thought I had was to gradually apply a charge to the solar panels and then suddenly apply an opposite charge, causing the dust to be repelled from the surface, to be carried away by the Martian winds.

I've no idea if it would actually work or not, but it seemed an elegant solution that didn't require any moving parts.

Re:The Martian Dust (4, Interesting)

Scorillo47 (752445) | more than 10 years ago | (#8418999)

>>> The big problem is that the dust is so fine, it'd be very difficult to wipe it off with anything akin to a windshield wiper. You might remove the dust, but the grit would scratch the glass, eventually causing enough opacity that the panels would eventually be rendered useless.

Probably using a vaccum would not damage the glass. Although this approach also adds more complexity...

>>> One thought I had was to gradually apply a charge to the solar panels and then suddenly apply an opposite charge, causing the dust to be repelled from the surface, to be carried away by the Martian winds.

Unfortunately this will not work since the electrical charge is not uniformy applied in only one direction on the surface glass. The small irregularities of the surface will cause a variation in the electrical distribution over time - for example a small peak in the glass might be more positively charged compared with inner of a nearly-located scratch. The same thing happens on some dust particles - due to their free movement in the air, their electrical distribution will end up non-uniform as well. So they will end up attracting as magnets - the small peak will attract particles on their negative-charged part, and the scratch will do the same on positively-charged surfaces. Now, since all these materials are good electrical insulators, the non-uniform distribution will stick on for a long time.

Probably what would help is to use a blower that would wipe off the dust with martian air. The blown air needs to be ionized to prevent more electrostatic charge to add up by just blowing. The ionized air will have a weak electrical conductivity which will tend to "shortcut" the charged areas. Now, since the martian air is mostly CO2 this pre-ionization process shouldn't require too high voltages - the energy consumption would be pretty low...

Blue Sunset is NO Surprise (4, Funny)

Crypto Gnome (651401) | more than 10 years ago | (#8418805)

Opportunity has photographed a blue martian sunset

It just plain makes sense, when you think about it.
  • Earth
    • Blue Sky
    • Red Sunset
  • Mars
    • Red Sky
    • Blue Sunset

The whole solar thing... (4, Interesting)

Paddyish (612430) | more than 10 years ago | (#8418814)

I have a bunch of questions about this stuff.

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.

And what's stopping them from making a way to keep the panels clear? This is what contributed to the end of the Pathfinder mission...What is it about solutions to this problem that make them so difficult to implement?

Wipers add an extra mechanical system to worry about, but what about static fields? Maybe there could be a way to attract the dust to a specific area while keep the the panels clear?

mainly because people are ignorant (2, Insightful)

xtal (49134) | more than 10 years ago | (#8418935)

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.

Re:mainly because people are ignorant (2, Insightful)

flossie (135232) | more than 10 years ago | (#8419020)

Because the feel-good environmentalists have heart attacks when you mention the word nuclear.

Challenger. Columbia. Nuclear?

One word (1)

geekoid (135745) | more than 10 years ago | (#8419000)

Hippies

Firs7 post (-1, Offtopic)

Anonymous Coward | more than 10 years ago | (#8418816)

fate. Le7's not be that he documents an operating system OF AMERICA) is the for the record, I

Clean Solar cells, Do what porn stars do! (3, Insightful)

t0qer (230538) | more than 10 years ago | (#8418847)

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

Osama Bin Laden Captured (-1, Offtopic)

Anonymous Coward | more than 10 years ago | (#8418862)

Osama Bin Laden Captured [news.com.au]

In other news... Stephen King is dead.

color calibration (-1, Troll)

btharris (597924) | more than 10 years ago | (#8418883)

how do we know this blue is calibrated right? haven't other slashdotters questioned the color calibration on Spirit before? how do we know this "blue" hasn't been "sexed up" like the Hubble PR people are notorious for doing?

Because I want one in space (4, Funny)

Papa Legba (192550) | more than 10 years ago | (#8418916)

I suggest a solar panel Zamboni! If for no other reason that Zambonis are cool and a space Zamboni would be a magnitude cooler. Imagine the great PR if NASA could send back shots of there Zamboni working on another planet.

Sunset (3, Insightful)

Lord_Dweomer (648696) | more than 10 years ago | (#8418920)

So I'm curious. Lets say we colonized Mars. Because of all the coloring issues surrounding the Martian photographs, could someone please clarify whether we would actually see a blue sky when the sun set? Or is that just some optical properties of the camera?

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.

Compressed Gas to blow the dust off? (1, Interesting)

Anonymous Coward | more than 10 years ago | (#8418963)

Why not just install a little compressed gas canister and blow the panels clear of dust?

It might not be 100% effective, but surely it could get most of the dust off? There is already a manipulator arm on the robot... maybe add a little hose & nozzle attachment to it? Dunno...

And if there's an issue of contaminating the martian environment... cant you sterilize the gas? Is introducing any type of gas into the martian atmosphere an issue?
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