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Cassini Probe Has Camera Problems
xX_sticky_Xx writes "The BBC is reporting that the last billion dollar NASA probe, Cassini, (enroute to Saturn) is suffering from an unknown source of contamination on its narrow field camera. NASA has attempted to alleviate the contamination, which is causing a haze to appear around images, by "defrosting" it, with so far limited success. Another attempt will be made in January. If this problem can't be resolved this will be extremely disappointing. Cassini is set to expand our knowledge of Saturn more than Galileo did for Jupiter."
just take off the glass lens, and use the bottom part of your t-shirt to clean it off!
of course, putting 100,000 miles between the two of them could cause a problem...
I read the article, but it wasn't too clear what exactly would be. There isn't much in the way of dust for the thing to run into I would think. There isn't water to condense on the lense either. Would this be dust that the probe has brought along with it for the ride that happened to settle on the wrong part?
right, they measured the lens in inches, but the windshield wiper in centimeters, so it's too small to wipe everything off.
Quidquid latine dictum sit, altum sonatur.
What about plain old space dust? According to this article there's enough of it out there to hamper astronomists when viewing celestial objects from earth. More closer to the point this article describes how people involved in space exploration are concerned with peices of space dust, too small to be tracked, causing serious damage to orbiting satelites. The Cassini article says they're pretty sure that it's related to the deep cold of space, which is why they equipped it with heaters. But if it's not related to the cold, it's not out of the realm of posibility that maybe Cassini simply encountered some of this dust? Although you'd have to think the makers of the satelite thought of this already, but who knows.
I posted to
Maybe it's time to start intalling windshield wipers on spacecraft?
This is a self-referential sig
I would only begin to worry if heating it a few more times doesn't clear it up totally.
So after reading the article (I know, rare for a slashdotter) I started wondering who they named the probe after. Turns out they named it after a 17th century astronomer who was the first to observe Saturn's four moons.
Some more info on the man behind the name of the probe can be found here.
I posted to
This is from the report sent out:
.Recent instrument activities included two Radio and Plasma Wave Science HighFrequency Receiver calibrations. Engineering activities taking place onboardthe spacecraft this week include an Attitude Control Subsystem high-watermark clear and the uplink of the Mission Sequence Subsystem (MSS) D7.6.1Modules.
Cassini Weekly Significant Eventsfor 12/06/01 - 12/12/01The most recent spacecraft telemetry was acquired from the Goldstonetracking station on Wednesday, December 12. The Cassini spacecraft is in anexcellent state of health and is operating normally. "Present Position" webpage, http://www.jpl.nasa.gov/cassini/english/where/
When I was 6, my mom bought this balloon for me. I accidentally let it go and it went higher and higher, never to be seen again.
Sorry NASA.
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Sometimes there's no other way to win, except by falling.
After all the risks that were taken to put this thing in space - it would be a shame for it to go to waste. (Risk = putting 75 LBS of plutonium within a few miles of crashing down onto the earth.)
NASA is having a rough time with it lately. There have been a lot of pretty expensive and embarasing failures. If NASA were a private enterprise I'd suspect a management shakeup. Since it is a government body - I'm not sure what can be done. Clearly something should be done...
Take care,
Brian
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We are almost out of Free Palm m100's...
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In news today, Nasa scientists spent all last week trying to find the source of the contaminant on the Lens. After many hours of brainstorming, one of the engineers spilt coffee on a button labeled "Lens Cap". Shortly after, the camera apeared to be functioning correctly. Head NASA Scientists are trying to work out the function of this "Lens Cap" button, but the British designer of the button cannot be contacted, and Nasa officials are still unsure what has happened.
it'll still be winter -- if we waited 'til spring and maybe it'd thaw out on its own.
when you take something from earth pressure to zero pressure you'd be surprised at what will boil off. this is called outgassing, as polymers, etc... lose mass to vapor. the stuff outgassed can then condense on your optics and ruin your pictures. The usual practice is to put everything in a vacuum chamber and get it all out before flight, but this won't always be enough. Also, you can coat surfaces that will outgass, but you need to use anyway (such as electronics circuit boards) with a non-outgassing coating (such as uralane). If some electronics overheat and melt away some of that coating, the materials underneath might, you guessed it, outgass. It is a difficult problem to avoid and it is unfortunate that it might ruin the mission. hopefully not.
This just keeps happening--the Vogon interstellar starliners keep illegally flushing their toilets into space in the vicinity of solar systems. I think we should file a complaint with the local authorities on Alpha Centauri.
The sucker was visible for a LONG time as it rose (very little wind that day). We promptly forgot about it, until about 6 months later. Turns out it ended up in some farmer's field about 200 miles away!
Yeah, completely offtopic, but further proof of just how geeky I was in those days. Thoughts like this are what inspires people to send probes to other planets, I guess.
Endless arguments over trivial contradictions in books written by ignorant savages to explain thunder in the dark.
The BBC article refers to the "Stardust" project as though everyone knows about it...
Stardust project, which had a similar problem that was much worse. In that case, Stardust's team were able to completely remove the contamination
You can read more about that mission at http://stardust.jpl.nasa.gov.
What a name.
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Give me LIBERTY, or give me a check.
Maybe it's about time for some fancy inter-stellar windshield wipers. I suppose it's hard to refill wiper-fluid in space though ;-)
I told ya we shouldn't have let that guy with the squeegee wash the lens on the way to Saturn!
If dust got on the lens, or inside, most likely the fuzz pattern would be even or random. The fact that it is on the edges of the image suggests that something is condensing.
If the camera was hit by a speck of space dust, perhaps the impact could have created a little cloud of dust when it penetrates (assuming it did not hit the lense or image sensor chip itself. If it did hit one of those, I doubt it would be just the edges.)
The fact that a little heat reduced the problem is also kind of against that theory.
Condensation of something is the most likely exlanation IMO.
Table-ized A.I.
A Jovian toddler mistook the probe for a scooter. Unfortunately, her parents forgot to put the toddler's diapers on.
Or, they forgot to turn on the No Smoking sign.
Table-ized A.I.
because you only get one chance to road-test it.
(Although parts of older designs are re-used, the only way to space-test the final product is to launch it.)
I wish they would launch 2 smaller probes rather than one big one. Split up the science instruments between them (but put high-res cameras on both). They used to do that in the 60's and 70's. Mariner 9 had a companion that croaked IIRC. Same with Mariner 2 and 4. (One of them was due to a FORTRAN typo between O and 0 (oh and zero)).
The failure rate has been constant over the years more or less, yet the costs have dropped.
The Soviets lost 3 probes at Mars IIRC. I believe their Venus probes were more successful because the atmosphere is so thick near the surface that landing is a breeze (no pun intend.) It is like an ocean there. Even if the probe was dead, it would still land smoothly.
Table-ized A.I.
Seriously though, one wonders if this could be even remotely related. I doubt it highly, but it is an interesting thought...
"They do not preach that their god will rouse them, a little before the Nuts work loose." Kipling, 'The Sons of Martha'
I'm not quite sure what the big deal is. They said in the story that not only were they optimistic that it would be fixed, but that the lenses and optics are designed with heaters for this kind of thing. Shouldn't we be happy that finally one of those "just-in-case" prevention measures that NASA spends millions on finally might be the difference between a successful and, well, not-so-successful mission?
It sounds to me like a lot more information needs to come out before we start saying that the mission is even in danger...we do have 2+ more years.
JoeRobe
The best way to predict the future is to invent it.
The source of contamination *has* to be the spacecraft itself.
If the contamination were external, it would have had a signifigant (measurable) effect on the momentum of the spacecraft. The space through which it is travelling is pretty much completely empty anyway.
That leaves one plausible possibility: Cassini is leaking something that is condensing on the cold (*very* cold) bits. The most likely cause is a small propellant leak. As far as I know, the spacecraft has three propellants on board, N2O4, N2H4 an monomethyl hydrazine. I'm too lazy to look up the charecteristics of these, but their boiling points differ.
A heating cycle of the lens seems to have helped. I would be *very* surprised if the data from the heating cycle didn't give them a good clue as to the exact contaminant by looking at the amount removed by a known heat input (latent heat of vapourisation)
The big worry is that the leak will leave the spacecraft with insufficient fuel for orbital insertion (unlikely - it's almost entirely a gravity-assist trajectory) or for manoeuvering. That would be bad.
I may, of course, be completely wrong.
Normally I'd laugh at that, but I do need to point out some technicalities. First, "crap" is a relative term. Yeah, if Dell tried to sell computers that worked as frequently (or infrequently) as NASA probes, it'd be out of business. Then again, Dell, Intel, AMD, Western Digital, et al all have the chance of trying their machinery out in real-life situations before putting it out on store shelves. How fortunate for them, but NASA doesn't have this luxury. Take a look at lunar missions starting in the early-to-mid sixties - see how many craft NASA shot up, and how many MORE Russia pumped up there. Then look at how many succeeded - you'll see a difference in approach right there. Russian mentality: keep trying, and if it drops out of the sky or flys by the moon or crashes, try it again! Just keep trying, and eventually you'll get one to work. NASA, on the other hand, has the opposite approach - make like the first shot is the only shot. Try to make sure it works as best as it can, then send it up. Maybe this is a result of a much more nosey press in America, or maybe its just the way Americans work.
The spacecraft up there are the pinnacle of technological achievement. Go to http://nmp.jpl.nasa.gov/ds1/ , Deep Space 1's webpage and read about this amazing spacecraft if you don't believe me. Just to cut some people off right now - yes, the cpu's aboard these spacecraft are exceedingly slow (I'm talking PI or slower), but they are doing things longer and more continuously than any desktop here on Earth. Finally, if you want to see a spacecraft that has lasted longer than most of our cars, and acquired a lot more data, see Galileo's latest stat, as it's in its third extended mission and still going stronger than ever: http://www.jpl.nasa.gov/galileo/
Just my thoughts,
JoeRobe
The best way to predict the future is to invent it.
It is the ONLY thing I LOVE about USA. I guess many foreigners feel the same way. There is bound to be problems, after all, it is rocket science. That is the agency brought Apollo 13 crew back, how hard could it be to clean a camera lens? Or just bring amazing amount of information with a faulty cam. It is one of two, after all, and there are other data collectors. Have some faith, NASA will solve... Unless your stupid president and idiotic congress cut their budgets further, not leaving enough staff to maintain the lonely probe. Remote possibility? No, just look what had happened to voyagers and pionners.
Gentlemen, you can't fight in here, this is the War Room!
Okay, most of the folks here seem to be bashing NASA and jumping to conclusions that the probe is lost. No damn way. They'll come up with a solution soon enough - for one thing, a similar incident occured with the Stardust probe earlier this year. Just take a look at the status reports.
Start at somewhere aroud May 4,2001 and go backwards (by that report, the problem had been fixed). I bet the glitch on Cassini will be fixed just as easily. Note that the problem occured just before christmas, so they probably just tried a "quick fix" to see if it just went away. Like said, they have until 2004(!) 'till Cassini is at its destination to try a number of things. They'll probably get rid of the contamination just by turning on the heaters for a couple of months, but they don't want to start the operation and immediately leave for a christmas vacation (in case something comes up).
For individual crafts, you are correct that soviets didn't care to lose one. But that was not a difference in engineering mentality, that was a (good) side effect of not having to disclose failures to public. So they could launch and learn, instead of going thru cumbersome process of checking and rechecking and then some more checking. Would you really care if you send ten times more probes to each target and have five times more failures? I thing it is sensible for unmanned missions.
Gentlemen, you can't fight in here, this is the War Room!
"Do something man. Right now."
Yes. Of course it would affect the momentum. But if the leak is slow enough for the vapour to remain close to the spacecraft for it to condense in large enough amounts to obscure a lens, I doubt that the velocity of the escape is enough to have much effect on a six-tonne spacecraft.
"You are dead wrong about 50ties and 60ties russian mentality"
Well, I get this idea of Russian space mentality from several (Russian) friends that followed Russia's space program during the 60's. In any case, I said that the mentality was "keep trying until one works." I didn't say that they had no direction, just that they had a different mentality while going in that direction. They could certainly have had it all planned out, but how they got there was different from the way that NASA would have done it.
Look at the numbers, the Soviets had far more failures in considerably more attempts, especially in the lunar lander department. I agree with you that this "not caring if you lose a craft" mentality is probably a result of not having to disclose failures to the public. But I think it's a mentality nonetheless, and it's one that the "states" did not have. Maybe it's just our definition of mentality that's different - it sounds like I'm calling "mentality" what you would call "technique".
In any case, I agree that only recently (until the early 90's) has NASA shown any real planning for the future.
The best way to predict the future is to invent it.
Well, I get this idea of Russian space mentality from several (Russian) friends that followed Russia's space program during the 60's.
I wish I had one of those. I have to rely on books instead.
Gentlemen, you can't fight in here, this is the War Room!
From the 10/25/01 - 10/31/01 weekly status report:
The Imaging Science Subsystem (ISS) post-warm-up images were downlinked for analysis. The 15 images were planned in support of the UVIS Spica observation, and were examined for potential changes relative to the pre-warm-up images. Preliminary results show a change in the character of the anomaly with the halo gone but more spreading of the star image than before. ISS also performed a scattered light observation, in an effort to resolve an anomaly observed in C25 when an ISS observation received far more light than expected. This current observation included a series of scans across the sky to see how much scattered light ISS gets at different distances from the sun for a selection of different orientations, to see if reflection off another part of the spacecraft is causing the extra light seen by ISS.
There are 10 types of people in this world, those who can count in binary and those who can't.
Learn basic HTML, then submit in 'HTML Formatted' mode.
<A HREF="http://www.nasa.gov/";>More info on NASA</A;> as an example of a link More info on NASA
Also <BR> for line breaks and <P> for paragraph breaks.
It has become appallingly obvious that our technology has exceeded our humanity. --- Albert Einstein
IF you had read the article, you would have realised that Galileo was the first to observe JUPITER'S four (largest) moons and SATURN'S rings.
Galileo is one of the world's most famous names. How could you have gotten far enough in life to be able to post on Slashdot without having heard of the guy?
You Fucktard.
The time for school is during a recession.
That very much depends on which hemisphere you're in... January's the second hottest month of the year for us... coming close behind Feb...
Does anybody remember there were protests against the launching of the Cassini probe? Some environmentalists were afraid about the nuclear materials aboard or something like that...
Hmmmm....
;)
Are you sure it isn't little green fingerprints on the lens?
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Once: you're a philosopher. Twice: a pervert.