Slashdot Mirror
The Forgotten Huygens Experiment
jdray writes "An experiment onboard the Huygens probe didn't run as planned because someone forgot to turn it on. The team lead for the experiment has put eighteen years of his life into the project, just to watch it not happen after a seven year ride to its destination on Titan."
Sounds like my life.
1. Doh
Doh (d)
Interj.
a) A Gen-X colloquialism conveying an overall feeling of frustration.
b) Used to express a feeling one has after realizing they have been tricked, misled, scammed, swindled, etc..
c) Used to boast or chide the victim of such tomfoolery
d) Coined by the animated sitcom character Homer Simpson in the mid to late eighties, "Doh" is similar to other one word, one syllable explicatives in that it is a quick and succinct summary of one's aggravation, but differs in that it was an accepted substitute to similarly censored words.
Damn that's sad. Don't they have checklists for these things??
Martin
This post is from memory. Please feel free to correct errors and ridicule me for factual inconsistencies.
I forgot to turn on my cellphone this morning, and missed a call from someone dear to me. Still, reading this makes me realise that somewhere out there, someone is feeling even worse over forgetting to turn something on.
Everything in the world is controlled by a small, evil group to which, unfortunately, no one you know belongs.
... especially in this field of work. If you have a project this big, the chance that nothing will go wrong are simply infinitessimal. Do you remember the last time when you wrote a program of 100 lines without doing a single error?
We should really praise the gods that the rest of Huygens mission was a grand success.
The creatures outside looked from Alt-Right to Antifa; but already it was impossible to say which was which.
Welcome to the real world.
Put this guy on a suicide watch. I'm about as far removed from this as anything, and *I'm* depressed...
Lets just hope noone forgets to turn on the anti-missile lasers on the orbiting satellites. Bigger mistakes can happen. :)
Codito, ergo sum.
I think they should have had this device automated like everything else was, after all, there was a 87 minute time delay on communication. A backup to the system that turns on after a set time if the primary doesn't would be nice too, but I bet weight limits scrapped a backup for most things (one reason why Beagle 2 went missing). Would have been cool to know the wind speeds, the photos showed it being tumbled aound a lot during the descent. At least the rest of mission worked. They managed to get the 50% 'missing' data now from the second transmitter. Radio telescopes picked them up, instead of Cassini. (http://news.bbc.co.uk/1/hi/sci/tech/4193043.stm)
I am looking forward to many more Titan missions. Its certainly more geologically active than Mars.
i spent 23 years of my life to get a girlfriend. i deleted all my pr0n for her. now she is gone. life is truly a misery.
I never understood why the apostrophe is there. What letter has been omitted? Maybe Homer somehow believes that saying "some water" in French is swearing or something.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
... a link to today's /. poll
Damn the bad luck....
Jaysyn
There is a war going on for your mind.
The point is, the radio channel that was never turned on was human error that caused the loss of half of all of the data from the probe. People's hard work functioned perfectly. Pictures were taken, data sampled, lander functioned correctly, no metric numbers were mistaken for imperial units, and they still lost half the data because someone screwed up.
Thats not a grand success. Compared to crashing a lander into Mars, losing everything? Yeah, its probably a grand success. But thats a pretty low standard.
The article isn't quite correct. A fuller description would take a while to type, so I summarise:
Two redundant radio channels were used to get data from the lander to the orbiter, which relays the data to earth. The signal for the orbiter to start listening on the high-sensitivity channel, channel A, was never given. The data was transmitted redundantly on both channels, except for images and the output of the Doppler wind speed experiment. Fortunately, all was not lost, as scientists donated radio telescope time around the earth to search directly for the A signal, despite it not being relayed via the orbiter. Thanks to this increase in sensitivity, the data acquired was good enough to fulfill all objectives of all experiments.
So everyone can relax and get one with the analysis...
I'm sure they'll have plenty of time to try again.
They send these missions all the time don't they?
The Joint Institute for VLBI in Europe (JIVE) has reported that the Huygens signal has been picked up by several Radio Telescopes on the ground. There was already a plan in place to investigate the Doppler on the signal to learn about Huygens' descent profile.
Also, the most recent ESA press conference on Huygens stated that they are trying to recover data from the ground telescopes (which they are now referring to as Channel C), although it was unclear if this would be just the signal's Doppler or actually decoding some of the lost data stream.
I assume (like practically all scientific projects) grad students were involved in the design. While the failure to turn on the experiment may be an embarrassment to the primary investigator, how does it affect the grad students? Do they just leave the "results" section of their dissertations blank? Do they need to restart their graduate research with another project?
Everybody knows the Huygens probe. Nobody knows any of the scientists who worked on the probe.
Now, David Atkinson has become a name.
Granted, he's that-guy-of-the-Huygens-mission-who-was-screwed- out-of-his-experimental-results-due-to-a-stupid- mistake-on-the-part-of-a-programmer, but at least people know him!
He can write a book! He can go on talkshows!
He can even use the fact that he is now a name to get more funding!
After the initial feeling of depression, he should realise how lucky he is.
And think of it, are you still interested in the things you thought up eighteen years ago (apart from screwing eighteen-year-olds)?
That article is written by someone who has *no clue* as to what it is they're writing about. It makes no sense and is self-contradictory.
--
Toby
I guess project managers aren't worthless individuals after all.
This article has recently been linked from Slashdot. Please keep an eye on the page history for errors or vandalism.
Find the person who was responsible for this, send him or her up there to turn it on, and tell them not to expect any overtime for it. In fact, the costs for sending them up should be taken out of their salary.
Might sound a bit hard, but it's the only way they'll learn.
The belief in a biblical god is an ignorant one
They dont check the accuracy of any posts, which, in my view is a bit lazy, but whatever... there's only 10-20 stories a day...... yet they cant read the blurb? Bah.
The first scientific assessments of Huygens' data were presented during a press conference at ESA head office in Paris on 21 January.
Results include:
And French for some water would be "de l'eau", not "d'eau". "D'eau" would be used to mean "of water" - "une bouteille d'eau" == "a bottle of water".
Try NetBSD... safe,straightforward,useful.
Isn't it wierd how bad an event is can depend so heavily on how it happened? I mean, I'd be pissed if this happened to me but I think I would be less pissed if it was due to component failure rather than human error (actually, sounds more like process or Q/A error, but I digress). And even if it was component failure, couldn't that (often) be ultimately traced back to human failure somewhere further up the line.
I dunno, we humans are strange.
This one gang kept wanting me to join cause I'm pretty good with a bo staff.
It would be fantastic if they could, but I think they are only talking about using the phase/doppler shift of the carrier signal to infer something about the location/movement of the probe. The high frequency data channel is probably lost in the noise.
:-)
As someone who has been involved in large coding projects (100,000 lines +) while I understand how easy it is for bugs to creep in, I do think the programming bug that effectively did not switch on the second channel should have been picked up on a project of this size/budget. Sadly, too often, the bigger the bureaucracy, the more mistakes like this you have - small keen teams often do better.
Regarding image quality on Huygens - in hindsight could that have been done better?
I realise there are constraints - 80's hardware, limited batteries, 8k bit channel, etc, but here are my casual observations..
Much higher resolution CCD's were available at the time - Cassini had a 1 megapixel unit. Low res data could have been transmitted during descent, but hi-res data could have been stored & broadcast after landing. As it is, the radio spent a lot of time sending identical images of the landing site. Another idea that gets a lot more out of a video data stream is variable jpg compression & only transmitting the signal difference between certain frames. That way you can use hi res CCDs then compress-until-it-fits the 8K data channel. When there is a lot of data/change in the pictures you compress a lot, but if certain cameras are not returning any or little change in the pictures, or if the picture has no detail, more channel space is available to send either hi-resolution or even pre-recorded data.
Furthermore, why the assumption that the probe will be destroyed on landing? Why not switch off Huygens when Cassini dissapears below the horizon, and switch it on for the next day? (titan's day is 16 days long..) The batteries lasted many hours after the landing, and the craft did cruise in standby mode for 16 days, so this might have been possible.
I think they could have returned all the data we got anyway up to the landing, and designed a 2nd phase with more data being sent, with little change to mission profile/weight/etc..
One thing I dont understand - why are the triplets out of sequence? The early pictures show the landing site! Is this just some artifact of the transmission process?
If I didnt know any better, I would say that final picture of the rocks was just a "joke" by the programmer, a frame to put in when the data/checksum fails for that camera..
"You lied to me! There is a Swansea!"
Many of us downloaded and listened to the audio of the probe falling through Titan's atmosphere... could it be possible that processing the audio with known things such as downward velocity of the probe and assuming what it was flying through was methane (or whatever hypothesized atmospheric makeup), etc could yield similar wind speed estimates?
Reminds me of this story, probably apocryphal, that said that Daniel Webster of "Webster's Dictionary" once had his life's work destroyed by an angry wife. Immediately after she'd burned (??) his work in the fireplace, he took out a pen, walked to his desk, then started again from the beginning.
This isn't the first or the last time this sort of thing has happened. A minor issue about metric vs. imperial comes to mind, and didn't someone forget to remove a lens cap from the Hubble space telescope before it launched?
"Hey, perfessor, lookit, we got us a high resolution image of the 'REMOVE BEFORE LAUNCH' galaxy!'
Cole's Law: Thinly sliced cabbage
...DOH!
But Officer, I DID read the f**king article!
It's kind of funny that these big mistakes can still happen, even after unit miscalculations causing Mars lander crashes and other embarrassing things. You'd expect they'd try to simulate as much as possible before launching it? In the former case with the Polar Lander (?), simulating the software, and in this case simply trying to get readings from the instruments? But since I'm literally not a rocket scientist, there just has to be some severe difficulties in making checklists by routine and simply trying the various features out?
Beware: In C++, your friends can see your privates!
It probably wasn't very important in the grand scheme of things,like most things. He has a good atitude about it but it must hurt in many ways. That's life I guess. Not everything was meant to be and this is one thing. I guess the speed of the winds on some moon of Saturn are not very important in the eyes of a greater power, if such a power exists. Else, someone's head has got to roll.
"If you are a dreamer, a wisher, a liar, A hope-er, a pray-er, a magic bean buyer
Why don't we just send up a staffed mission, and have done with it once and for all?
Obviously, this would have to be a kamikaze mission. But is that such a bad thing anyway? Throughout history, explorers on Earth have set out knowing they might not return -- and many did not return. Even Christopher Columbus knew there was a risk that he could be wrong about the Earth being round. Of course it's best if you can be a living legend, but if you have to settle for one out of two then it's surely better to be a dead legend than a living nobody. That is the spirit of adventure, and it's ultimately why we climbed down from the trees and started walking around on two legs. Not to carry it on now is a mark of disrespect to all those brave people who traded their lives for the advancement of science.
So why not a one-way ticket to space? People have given their lives for much, much less than priceless insights into the cosmos.
Je fume. Tu fumes. Nous fûmes!
off. site. backup.
women come, women go, but pr0n is forever
Suchetha
learn from yesterday, plan for tomorrow, party tonight
or one out of three ain't bad
At it's best. Now can he be sued for not completing his work?
Doesnt this get automatically entered in slashdot's latest poll? :P
(If it were a contest, this would win it by a landslide)
I feel sorry for the outcome of that root cause analysis. Would love to have been a fly on the wall when all that went down.
Grad students involved in the building are now either professors or burger engineers, depending on how good they were. There are grad students that got involved in the process later (like me), but we haven't invested NEARLY the time and effort as those that have been working on this stuff since I was in Jr. High school.
I've got to drive 40 miles on Monday to kick the ass of a broadband router that won't connect so I know how this guy feels.
AT&ROFLMAO
So far neither ESA nor NASA/JPL have anything to say about this, but I would assume this information came from the press conference that was scheduled for today.
Science fiction for grown-ups...
Well, I look at it this way:
They chose to use 2 links, thus increasing bandwidth, and the probability that one of them would fail. HOWEVER, is it not better to have had channel B work than A alone , but not at all ?
Then everyone would be screwed.
You think they'd put a software on/off switch on that thing.
I guess it'll be there for the next mission...
the major advances in civilization are processes which all but wreck the societies in which they occur - A.N. White
It's done that way specifically so that post processing gets the colour balance right. Other info is used to balance the colour. Hence the raw images are greyscale.
Did he inhale?
Wow, I feel bad for this guy...
When it is stated that the guy "put eighteen years of his life into the project", does that really mean that, for 18 years, he spent all his workdays (or at least all his research time, considering he is a University professor) doing nothing else but designing and building the hardware for this experiment?
This error was discovered at the last minute. What I heard was that they managed to measure it anyway with an array of radio telescopes. So the damage (apart from that to the researcher) was small. See also a link about this international effort.
This explains the phrase "eau de toilette", which translates as toilet water. Some French people use this as perfume. Usually, there is no second date when this is done.
Don't blame Durga. I voted for Centauri.
Black and white sensors have higher resolution, just as black and white film has higher resolution. Resolution is more than the number of pixels, it's the valuable ability to resolve actual data with those photosensors.
Your little consumer digicam that did not cost a hundred thousand dollars is arranged with cheap little colored filters, cutting out over half of the photons that arrive in the camera, just so you can get the right shade of pink on your girlfriend's tummy. Scientists would rather collect all the photons they can, thanks.
Scientists do use filters now and then. Spirit and Opportunity use black and white cameras, but they can use something like NINE different filters to block out all frequencies except certain bands of interest. They don't just select Red, Green, Blue, but also various bands of near and far Infrared and Ultraviolet too. Those probes were designed later, and were going to be used on a longer mission, where power and available light energy would be greater. Huygens was built earlier, and going to a distant and dark moon where they'd be lucky if the probe lasted a couple of hours.
Is their logic still a mystery to you?
[
self-contradictory
Nice tautology, Toby.
I thought that only a screen writer would use a plot that would have the 'channel B' have a less stable oscillator than 'channel A.' Then someone forgets to turn on channel A.
It looks like this experiment was doomed before the craft ever left the ground.
Edmund Blackadder: Right, let's get the book. Now; Baldrick, where's the manuscript?
Baldrick: You mean the big papery thing tied up with string?
E: Yes, Baldrick -- the manuscript belonging to Dr. Johnson.
B: You mean the baity fellow in the black coat who just left?
E: Yes, Baldrick -- Dr. Johnson.
B: So you're asking where the big papery thing tied up with string belonging
to the baity fellow in the black coat who just left is.
E: Yes, Baldrick, I am, and if you don't answer, then the booted bony thing
with five toes at the end of my leg will soon connect sharply with the
soft dangly collection of objects in your trousers. For the last time,
Baldrick: Where is Dr. Johnson's manuscript?
B: On the fire.
E: (shocked) On the *what*?
B: The hot orangy thing under the stony mantlepiece.
E: You *burned* the Dictionary?
B: Yup.
"You lied to me! There is a Swansea!"
Speaking as someone who have already done this experiment countless times, I can confirm that it indeed rarely run as planned, mostly because-- What? Huygens? Oh, I thought you said hygienes... Now, seriously. Needless to say, as many of you I have been looking forward to see the results of this experiment for quite a few years. Could someone please tell me who exactly was responsible for that mistake? Was that person fired instantly? Will that person face criminal charges and prosecution? Or will we just use euphemisms and say that it was another "glitch" and pretend nothing happened, silently approving this kind of inexcusable incompetence ruining the most important scientific projects, not to even mention all the money and other costs involved? Can we afford giving such a strong argument in the hands of our opponents? And there are people who say: "See? Scientists can only waste money. Let's give it to Vatican instead." What will we answer? That it was "just" two decade, "just" few billions, "just" a small mistake? I don't think so. We need to act and show that we will not tolerate such mistakes any more.
Sincerely,
Pan Tarhei Hosé, PhD.
"Homo sum et cogito ergo odi profanum vulgus et libido."
"In total, the core of our team has invested something like 80 man years on this experiment, 18 of which are mine," Atkinson wrote. "I think right now the key lesson is this -- if you're looking for a job with instant and guaranteed success, this isn't it."
It sounds like some of his work will continue at least. Got to admire his attitude and perspective.
"The Sage treasures Unity and measures all things by it" - Lao Tzu
Main reason was to take pictures?
...but you probably won't understand those if you really think they send the expensive probe half way across the solar system just to take some snapshots.
No-no-no.
The reason pictures were received first and are getting most of the attention is because it's good PR. A lot of scientific data isn't pretty things you can oogle at, but just some measured numbers at chart. Describing atmospheric composition, pressure, and so on.
You have no excuse: I wrote it on /. 6 days ago.
You know, if I were this guy, I would have been calling them once every five minutes saying, "Hey, did you remember to get my experiment going?" If it's really that important, why let someone else screw it up for you? It's your baby, your responsibility.
"Give a man fire, and he'll be warm for a day; set a man on fire, and he'll be warm for the rest of his life
They use monochrome images for a very good reason.
To capture a colour image using CCD arrays, there are the cheap, the expensive and economic ways. The cheap way (consumer cameras) is to place itty-bitty colour filters over the entire CCD array. In this way each cell captures either red,green,blue or white.
The expensive way is to have separate CCD chips for every wavelength of light you want to capture.
However, when an image is captured by a CCD array, there is a very small amount of bleed from one CCD pixel into it's neighbours. You can compensate for this by making use of image process techniques like convolution/sharpening. But these methods are completely useless with the cheap way of capturing colour images (each of RGBW will have blended with its neighbours of a different colour).
This can be done with the expensive way (professional digital cameras), but you are restricted to three wavelengths of light.
Alternatively, you can have one CCD chip, and a series of calibrated colour filters that can be swapped over. In that way you, have a low energy budget of one CCD chip, and the flexbility of analysing a scene in multiple light wavelengths, each of which can be processed separately.
Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
This is what the slashdot post says...
But I got this out of your linked article...
And I also found this article online. Here's an excerpt...The reports are confusing and I can't tell what happened. Was there a measurement device onboard the Huygens probe gathering data and transmitting it (like the Slashdot story suggests), or was the data supposed to come from the measurement of the signal from the Huygens probe in relation to the Cassini orbiter?
If it was the former, is the data not as good because the Earth radio telescopes didn't pick up the entire signal, because there was signal degradation, or because they have to piece all the data together from all the different radio telescopes? If it was the latter, is the data not as precise because of the proximity from the transmitter to the receiver?
Either way, the Slashdot post is wrong. If it was a measurement device solely on the Huygens probe, it was turned on- it was the relay onboard the Cassini orbiter that wasn't turned on. If the data was meant to be gathered from the proximity of the transmitter to the receiver, then the experiment wasn't onboard the Huygens probe but was actually meant to be a collaboration between the probe and the orbiter.
Oops....
Charles Perrow has an excellent analysis of those type of accidents in Nuclear Plants, Petrochemical industries, Aircraft & Airways, Dams etc.
(Normal Accidents: Living with High-Risk Technologies, by Charles Perrow, Basic Books, NY, 1984.) http://oak.cats.ohiou.edu/~piccard/entropy/perrow. html
Most of these accidents and failures were not the result of lack of money or due to operator error. In this case, I doubt it was a simple as forgetting to push a button on a control panel. This is not an excuse, but a reasonable explanation for a whole range of accidents involving complex systems.
black and white film has higher resolution
Myth.
Like woodworking? Build your own picture frames.
I saw an interview on the Canadian Discovery Channel, they interviewed the guy who made the probe that would determine what the surface texture was like. He spent 12 years making it and it did its job in 1/20 of a second. He laughed, nice to see he has a sense of humour. He said the surface was like Creme Brule.
When the ESA does something stupid, please remember to ridicule it as much as you do NASA's dumb mistakes.
[ home ]
Aren't these mechanisms supposed to be pre-programmed?
by the makers of Play Doh for copyright infringement.
Personally, I thought the apostrophe was for a brief pause, so there's more emphasis on the D phoneme.
"No fair, you changed the outcome by measuring it!" - Professor Hubert J. Farnsworth
Someone should tell him to come post in the /. poll...
Now that's what you call the start of a very bad day.
28:06:42:12 - That is when the world will end...
Now they feel like many of the parental units of the /.ers :)
We admit all this to insure disbelief
You can find more detailed information about this sad story in Nature.
Sorry, but where did you read this??? I'm a photographer myself and this statement is simply not true.
And how can you possibly tell that was not a sabotage before the investigation? I'm sorry but I don't believe that making it yet another "glitch" swept under the carpet and turning blind eye is a better idea than actually finding out what really happened.
Sincerely,
Pan Tarhei Hosé, PhD.
"Homo sum et cogito ergo odi profanum vulgus et libido."
The guy spent 18 years of his life for a wind measurement??? That man must really love wind.
+1 Insightful, -1 Troll. What can I say, I'm an Insightful Troll.
Perhaps not higher resolution, but when you're on a planet with 1/100th the amount of sunlight as the earth, you'd probably be wise not to be filtering any more of it out trying to get color pics.
Kodak Techpan.
One of the articles, I can't recall which, stated that NASA executed the package (whatever that is) delivered to them by ESA. It seems like there should have been a Cassini simulator to test these packages on. That, plus a checklist with an entry like "Receiver A on".
I would have run it on a sim at ESA and on a sim at NASA (the package should come with a checklist) and with independant review and verification to boot.
This sig intentionally left blank.
Who in aerospace makes the checklist for all the unknown errors, say, like a cosmic ray taking out a random flag bit in a register. I would like to know since if IRC, NASA and ESA projects are CMM level 5. As far as I know even CMM level 5 projects, that have checklists up to thier eyeballs, still can't find those pesky unknown problems. Human error is probably at the top of the unkown error list but even knowing that, it still persists. Checklists are essential and also doomed to always be incomplete, like every other system they can and will fail. Any honest quality expert will tell you the same thing, "there are no absolutes, shit can happen, a good QA system will minimse the chance of shit happening to your project".
Maybe your customers belive your "pilots are infallible because of checklists" theory, but it's been my experience that after the "shit happens" a book full of cross checked checklists will only help you to repeat the shit in exactly the same way (learn where you went wrong). This is what happened here, they will learn something from this dissapointing hiccup in thier extremely accururate data collection and navigation system that will keep operating for years. They will go back to thier libraries of checklist and find out why thier system partially failed in this instance.
Considering your job, it kinda scares me that you think "it's not hard", but with all due respect, writing embeded software in an environment refined by many plane crashes over many years is nothing like shooting a bus through the rings of Saturn for the first time.
Systems are created and operated by humans and every human makes mistakes, even perfectly regimented pilots. The person, people or team(s) that made this mistake will feel bad enough without a pompous pilot telling them they are incompetent.
Or in your own words... "We take it for granted that they are properly designed with failsafe modes"..."those are just admissions of shoddy management and operations"
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
What part of "resolution is not just how many pixels" escaped you? Signal is the actual photon counts given, the charge built from all the incoming light energy. You want the strongest signal possible. Noise is the level of spurious charge buildup from heat or transistor variations. You can't get rid of this noise in the system. You can try to minimize it in the design, but you still have to deal with some. If you're filtering out any photons, the signal-to-noise ratio falls. Subtle details just above the floor of noise for an unfiltered sensor would be far below the noise for a filtered sensor. Thus, those details are lost. Just being a photographer isn't enough. Have you actually used an electronic camera that has a sensor without color filters?
[
I dunno, I think they would be putting the beatdown on every bug in sight at that meeting...
"Learning is not compulsory... neither is survival."
--Dr.W.Edwards Deming
Ignore 'em.
Don't drive to work, personally. Trashed too many cars commuting. I take the bus.
"Learning is not compulsory... neither is survival."
--Dr.W.Edwards Deming
You may be technically correct, but what I wonder is, has NASA just given up on trying to fire people's imagination? Would ONE full-color shot to replicate what the surface would look like if you were standing on it hurt? Would it have been so bad to have a microphone that didn't record everything as "SHHHHHHHHH?"
:(
I was not disappointed in their achievements, but they just completely blew ANOTHER chance to get people interested in space. Way to go
By not turning on both transmission channels only 370 pictures were transmitted out of 700 expected if the experiement ran to completion. Still the 370 were fabulous.
Professor Frink: "The Huygens glavin with the switching and the OH NO not working..."
Developers: We can use your help.
Aussi, mon clavier n'a pas les accents (et aussi il est foutu, l'espace march 1 fois sur 4) donc je dois faire les "ampersand-eacute" conneries. Putain de merde, c'est chiant.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
>Main reason was to take pictures?
>
>No-no-no.
Oh yes. The scietific data is all well and good but theres a reason that almost ALL space probes have had cameras - thats how we explore the world , by sight. No one apart from a few scientists gives a rats bottom about a screen full of figures but show people a picture and it makes all the difference. Besides, you can have all the measurements of wind speed, temp, acidity etc you want , but you still won't know what its like there without a picture.
What's wrong with these people!? First they don't fully test their equipment, and it takes a determined man to show them if they don't correct for the doppler shift, they'll loose everything. Then they forget to turn on a second channel.
I'm not specially trained, I'm not a scientist, and I don't know anything about how to run their experiments, but the fuckin' Stooges could do a better job than this! Ever fly a small plane? They have a checklist for a reason... so you don't "forget" that all important step! My god, these people need to take a class: "How not to fuck up - 101". /rant
You my friend have never been to Quebec. And I'm not talking about Montreal. Try small-town Quebec. That's where real french is spoken.
There's no Canada like French Canada,
It's zee best Canada in zee land,
Zee other Canada is a bullshit Canada,
If you lived here for a day you'd understand!
Downmodding is the refuge of the weak. Don't downmod, make a better argument!
If you are paying for it, you are doing it wrong.
Who met his defeat at Water Loo. Which, of course, is a slightly redundant-sounding British term for toilet. Puts us right back on topic!
Don't blame Durga. I voted for Centauri.
Which is, what's the most expensive hardware you've ever ruined?
It's not wasting time, I'm educating myself.
Wasn't it this mission that carried a nuclear reactor that used plutonium? And to get to Saturn, NASA swung the craft in a near earth slingshot effect? I remember being stunned to learn after the fact that a wrong calculation would have led to a disasterous burn-up in earth's atmosphere. Articles at the time were saying that these guys are good and miscalulations just don't happen at this level of engineering excellence... Yeah, right. I, for one, do not welcome our glow-in-the-dark overlords.
Say hello to my little sig.
We'll send an astronaut in cryo so he can turn the switch back on :)
I'm actually curious, and this is an actual question (not a troll), so I'll ask again: is the reason that we don't hear so much of nasa's successes because they're so common that they're not news worthy, or because there aren't any?
I mod down anyone who says "I will be modded down for this", regardless of the rest of their comment
I read that also, and it seemed like they might not have all of channel A - but I was wondering how much they did get, and can't find any good reports on that.
I guess they are probably doing a lot of signal processing work right about now to coerce more A data from incredibly faint signals...
I wonder also if this will mean more pictures later on.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
Pilots use them.
Submariners use them.
Good software testers use them.
When you absolutely have to get it right the first time, build a check list. No matter how boring it is. They may prevent you from wasting 18 years of your life, or dying.
putting the 'B' in LGBTQ+
From everything I've read at Space.com. Nobody forgot to turn on this experiment. The problems was that ESA sent NASA poor specs that didn't include the proper instructions. Things went up as they were described in the manual which meant the experiment was not turned on. That said, nobody forgot they just didn't document it correctly.
The scientist who's got nothing to show for the last 18 years of his life said, "I think right now the key lesson is this -- if you're looking for a job with instant and guaranteed success, this isn't it." No, sir. Acutally the lesson is much simpler - USE A CHECKLIST! Besides, what's "instant" about 18 years? And what's "guaranteed" about NASA? This guy just has a problem with the Obvious things in life.
According to this BBC report they've recovered most of the lost data by receiving it directly from the Huygens lander using radio telescopes.
on the NEXT mission there'll be about a zillion "don't forget to turn on MY experiment!" e-mails, very likely with each one followed by several "me too!" e-mails.
This space intentionally left (almost) blank.
someone sends you an incorrect checklist?
In essences, this is what happend.
The Kruger Dunning explains most post on
Mishaps like these are what make me grind my teeth when thinking about NASA and the space program. I've always been a staunch supporter of the space program, but failures like these make me question their value. How could however many dozen PhD's who spent 18 years FORGET to turn on an experiment like this? You'd think there'd be an if (module.enabled) {} check somewhere in the code that would throw a master alarm in the else {} clause.
This is why Burt Rutan et al. will continue to succeed: failure is not an option! If you forget to enable a system that cost millions of dollars, you're out of business.
Not that the mission is a total loss. But I'm still baffled by how NASA can make these mistakes. They're the type of mistakes that give some credibility to the conspiracy theorists, arguing that NASA didn't really lose the Mars Observer, the Polar Lander, or the Mars Climate Orbiter. Rather, NASA found evidence of extraterrestrial life and is covering it up. We probably won't know until the second space race heats up, with China, India and perhaps Brazil, but also Rutan, Branson, Bezos, et al. gunning for the moon and Mars. Onward!
you have an internet connection, you do have an offsite backup of all the porn.
The Kruger Dunning explains most post on
would long now have his PhD...
You ass. Women grad students worked on the program too.
I'm sure he's taking it with grace, but frankly I'd say we should take up a collection so he can get wasted and trash an extravagant hotel room. I hear that's therapeutic.
-kev
You are now confusing "sensibility" and "resolution". The "resolution" of a digital camera describes simply the number of photo-sensitive receptors per surface unit. What you are describing as nothing to do with sensor resolution.
I doubt that the channel A data recovered via radiotelescope will be of much value to the doppler wind experiment. Consider that the recovered signal will be doppler shifted by:
1) The rotation of Titan
2) The orbit of Titan around Saturn
3) The orbit of saturn around Sol
4) The rotation of Earth
5) The orbit of Earth around Sol
I'm not saying it's an impossible task, but it certainly is a challenging one. If Cassini did not process the Huygens probe data (but simply recorded it and played it back during transmission to earth), and the radiotelescopes recovered channel B data as well, it might be possible to correlate the RT channel B data with that downlinked from the repeater on board Cassini. Then they could apply the difference to the channel A RT data and recover the original. Lots of assumptions on my part here.
I haven't read anywhere about the quality of the recovered RT signal but I also doubt that anyone will be able to decode much of the modulated data on it.
--
sigs are a waste of space
There is another issue to perhaps consider. Earth-bound studies found only one narrow frequency that seemed to penetrate the haze layers of Titan. If you have one narrow frequency that works, you are generally not going to be able to get usable color images.
For example, if only green light penetrated fog, then any other color than green would just show amorphous haze. It would not add any useful information to the image (other than varify that only green works).
I am not sure whether they used this frequency on Huygens or not. Anybody know?
By the way, it is not a frequency that human eyes see. Cassini's (orbiter) cameras were specially fitted with filters for this special frequency. The Voyager probes were launched before the discovery of this frequency, and thus could not see the dark splotches that Cassini sees on Titan.
Table-ized A.I.
Wow, props to the insightful, well-written post, low user number, and relevancy.
There may be hope for Slashdot after all.
sucks for that dood... i would of punched atleast one person in the face..
- Hi I'm Linus Torvalds and I pronounce Linux, Lih-nix..
I have this theory. If Titan is made of methane and no oxygen....what is preventing someone from lobbing essentially what would be a Molotov Cocktail at the moon and blowing that fucker up? I mean this is pretty simple. Send probe with a canister of oxygen with it, descend into the atmosphere, and issue a detonate command. Personally, I think that would be really fucking cool.
Results in Vishniac's experiment would have indicated the possible presence of a broad spectrum of life, but might not have been absolutely conclusive; positive results from the included experiments, it was thought, would definitively indicate the presence of some form of life. (As it turns out, depending on who you ask, that wasn't as hard-and-fast as the team would have liked: clays found on earth will duplicate the "life" indications of the Viking experiments, and the Viking data indicate the possible presence of such soil on Mars.)
Due to space constraints, Vishniac's experiment was dropped from the lander. He continued his research on extreme environments in Antarctica, where he met his death by falling into a crevasse while hiking from one of his sample stations to another.
Sagan's opinion was that Vishniac's experiment should have been the one included.
-- Old Man Kensey
Mike: "Bob, this is so great! We are about to receive data from Titan. I feel better that we have our two channels on."
Bob: "Two.....channels? Ugh....I gotta go use the....rest....room..."
Table-ized A.I.
To capture a colour image using CCD arrays, there are the cheap, the expensive and economic ways. The cheap way (consumer cameras) is to place itty-bitty colour filters over the entire CCD array. In this way each cell captures either red,green,blue or white. The expensive way is to have separate CCD chips for every wavelength of light you want to capture.
For X-rays, there is an even better method. In a typical exposure of astronomical sources at X-ray wavelengths, there will be at most one photon hitting each pixel during the exposure (X-rays are pretty scarce things). Now, the charge on a CCD pixel is proportional to the energy deposited in the pixel. If you know (or can assume) that the energy deposited comes from a single photon, then you know immediately from the pixel charge what the energy of the photon was. And, via de Broglie's relation, you therefore know the wavelength of the photon.
This principle is use in the ACIS camera onboard the Chandra X-ray space telescope. ACIS imagas contain not only spatial information, but also spectral information, albeit at low resolution. Which is pretty neat!
Unfortunately, the same principle won't work for visible light, unless you can get the exposure times (including CCD readout time) to be short enough so that each pixel is hit by at most one photon. Which ain't going to happen soon.
Tubal-Cain smokes the white owl.
What would happen? Probably about the same as if you dropped a canister of methane into Earth's atmosphere and detonated it. A big fireball, yes, but a canister of methane isn't going to consume all the oxygen on Earth. Nor will that canister of oxygen consume all the methane on Titan.
On Titan, warning signs reading "flammable" are posted in the oxygen mines (they extract small amounts of oxygen from solid-rock water), not around the natural methane lakes.
... but robust, high reliability systems should keep the shit from hitting the fan.
Perrow's a pessimist. His theory's good up to a point, but it ignores robustness. Look up "high reliability organization" and you'll find a wealth of information contradicting Perrow's main premise (i.e., that it's impossible to manage a system that exhibits both high connectivity and high interactive complexity).
Getting tired of Slashdot... moving to Usenet comp.misc for a while.
I dont even bother with editors and debuggers.
I write a program by typing into
cat > prog.java
I even pried off the backspace key off my keyboard because it was unnecessary.
It did; I watched the press conference on NASA webcast and I wonder if it's a misinterpretation of what Jean-Pierre Lebreton (Huygens mission manager) briefly tried to explain. He seemed to refer to the direct Huygens-Earth signal as "Channel C" and said they were still busy analyzing the recorded signal, but he didn't go into detail on whether the "missing data" referred to the lost pictures or to the failed doppler wind experiment.
As I understand it, both the doppler wind experiment on Cassini and the very long baseline interferometry experiment on Earth aimed at tracing the descent path of Huygens in Titan's atmosphere, though from different points of view (maybe either experiment had other aims as well).
It has been said that the signal from Huygens was much too faint for any data to be extracted from it here on Earth, only the carrier could supposedly be detected. I guess it's like listening on the shortwave band using a regular radio and noticing the presence of a weak transmitter, while the signal is so blurred you can't possibly make out what they are saying. But if aliens 60 light-years away are supposed to hear WWII radio broadcasts from Earth now, maybe it's technically possible for us to pick up a mobile phone call from Saturn orbit?
I think you misspelled "most of the time", at least from a remote sensing perspective. Landsat's Thematic Mapper, MOC on Mars Global Surveyor, THEMIS on Odyssey, the Viking orbiters ...all their camera systems used/uses filters and there are many more I am less familiar with that also use filters. The old Mariner missions used unfiltered vidicons (and I think 9 [Mars] and 10 [Venus, Mercury] did have filters, but I don't recall), but I'm hard pressed to think of many systems built since the 70s that don't use filters on their optical instruments. I will caveat by admitting my knowledge is very Mars-centric (or 'areocentric' if you prefer) and I don't know much about how the star cameras used for navigation are put together.
Collecting all the photons you can is a good thing, but knowing the wavelength of those photons is pretty darned useful too.
ohnoes!
I always assumed it was a contraction of "duhhhh... oh!".
For all intensive purposes, "whom" is no longer a word. That begs the question, "who cares"?
You seem to suggest they would have been able to correct the problem, once they learned about it. They weren't. Cassini is built with a minimum of moving parts (for robustness, I guess), and the whole vehicle has to be turned around for every operation that requires aiming at a target, such as Earth or some Saturnian moon. The entire list of operations to be performed for an event has to be uploaded to Cassini well in advance of execution.
Therefore, Cassini couldn't begin transmitting to (or listening for new commands from) Earth until it had finished listening to Huygens. When the first playback of Channel B arrived at Earth more than one hour later, not accompanied by Channel A, Cassini was already below Titan's horizon as seen from Huygens' landing site.
This is why radio telescopes on Earth were able to report a successful landing on Titan several hours before ESA had any data even from the early stages of the descent. When Huygens continued transmitting far longer than expected, and Saturn was about to disappear below the horizon to radio telescopes in Australia, ESA was engaging additional telescopes in Europe to continue listening. They may have been investigating the Channel A problem simultaneously, but there was nothing NASA could have done about it at that time.
suce ma queue
Simulation was also used by Boris Smeds for his elaborate testing of the Huygens-Cassini communications link in 2000. While he were to test the actual receivers on Cassini, he used the Huygens copy left on Earth to generate and record a sample data stream in the proper format. He then simulated the effects of Huygens descending along an irregular path, taking atmospheric interference into account, by carefully tweaking both the frequency and the power of the Deep Space Network transmitter used for the test. When Cassini returned perfectly clear garbage instead of the expected test data, he reworked his experiment until it became clear that Doppler shift was a major problem to Cassini.
That simulation covered only a specific component of the Cassini-Huygens mission, and I'm not sure the exact command sequence sent to Cassini in preparation for the landing had even been written at that time, so nobody may have been able to test it in a complete simulator of the entire system. Since the mission schedule was altered to deal with the Doppler shift problem, the command sequence would probably have required modification anyway, but the more you can simulate in advance, the better.
Rather than spend extra time writing a simulator from scratch, wouldn't it be better if the design process included simulation by default? I'm not familiar with how these systems are designed, but I suppose you could integrate simulation parameters with the technical documentation. Ideally, you should be able to execute the documentation and have the whole system begin operating virtually on your screen. Manual checklists are necessary as well, but you shouldn't have to rely on a checklist to make sure that all the different software components (and maybe even some in hardware) will cooperate nicely.
As the Channel A failure wasn't due to some unexpected natural phenomenon, but rather a glitch in the program, it would most likely have been detected by simulation. If a human is supposed to press a particular button at a particular time, you can simulate that too, or even find out what happens if the operator has gone fishing.
That's impressive. Space programs need people like him. You get the feeling that if there had been a Boris Smeds around before the Challenger incident, things would have gone a bit differently.
Ah well.
--grendel drago
Laws do not persuade just because they threaten. --Seneca
I do a lot of database development with a real database manager (PostgreSQL). One thing to understand here is that the accepted behavior of the database when asked to do something wrong is to "puke" and abort the entire transaction. If you try to handle things too gracefully, you get something like MySQL where what you put in is not necessarily what you get out. And if the hard drive is removed and the data can't be written, it is better to let the app know that nothing is being written or fail horribly rather than give the illusion that things are still partly functioning.
I think, however, you are right about your points, as long as I take it to mean that failure circumstances should be handled according to spec and what is the desired response to the failure.
Let me give you a story about bad QA which I was involved in. I lost pretty much all faith in large companies QA departments after this. This is when I worked at Microsoft....
I was helping to debug a failed application as part of compatability testing for server 2003. The issue was that Websphere 5 would crash on install (and would install properly on 2000 Server). I probably spent 2-3 hrs in front of a debugger trying to determine what went wrong-- what had changed between versions so that I could write it up and send it to the people who could fix it before the product was released. The issue isn;t that it is hard or that it is complicated. The issue is one of management priorities.
It turns out that the problem has to do with the way Websphere 5 installs its own JRE. It reads the current JAVA_HOME environment variable, resets it, installs the IBM JRE, and then sets it back to what it was originally. It then repeats this process later. This works fine in Windows 2000.
In Server 2003, if you don't have the environment variable set at the start of the installation, it tries to read the non-existant variable, and like in Windows 2000, this returns an empty, null-terminated string. It then sets the environment variable, installs the JRE, and then returns it to the cached old value, an empty, null-terminated string. Unlike with Server 2000, 2003 Server actually leaves the enviromnet variable set, but empty. When it goes to repeat this process later, it crashes on a system call trying to convert the empty string from Unicode to ANSI.
So this is what I tell the developers. I say that this is what causes the crash, and they promptly blame the program and IBM. I point out that this is crashing on a system call, and that the two API's for handling the environemnt variables don't work well together and that one should be changed, or at least the problem documented. And they refuse to do this. So this is where "professional" developers stand.
Looking at the money spent, and the multitude of man years spent on developing the lander for this mission, to hear that a significant experiment was lost becase somebody forgot to turn it on, is just beyond comprehension. this goes way beyond unprofessional, and well past the line we would draw for 'incompetent'.
Makes you wonder where the problem occurred though. Who forgot what? When was it forgotten? Was it some guy who forgot to turn it on, or was it some guy who forgot to include it in the agenda early on? I assume this is why they are investigating.
The good news is, not all data was lost, though.
LedgerSMB: Open source Accounting/ERP
Seconded, most definitely. Girls who hate porn tend to be the type that would even consider having sex to humor someone. Yech. I collect pornography from the vasty wastelands of TGPs (mainly from sources like AskJolene and Tiava, which include a great deal of crap that I wade through) and send it forth to my beloved, who shows her appreciation via a hacked Dakota that I sent her. (There, I have dork credibility. Nyah.)
I went through a lot of my first girlfriend telling me I was "sick, disgusting and wrong" (that's a direct quote) before I found out that not all girls do that, and that I'm not, in fact, sick, disgusting and wrong. A lesson well learned---I shall never date another non-perv, ever again.
By the way, what's the 'ACT'? What country are you posting from, and what do you mean by 'real porn'?
--grendel drago
Laws do not persuade just because they threaten. --Seneca
This is the same country where the age of consent for being in porn is sixteen, leading to an admonition I've seen in various places not to trust the United States-legality of anything you download from Australia?
Man, that's weird. And it'd be something of a bother, too, if porn came from porn stores and not too-trusting tennaged girls on the internet.
--grendel drago
Laws do not persuade just because they threaten. --Seneca