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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."
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.
Officials for the European Space Agency said last week they would investigate to learn what happened. They were not available for comment on Thursday, nor did NASA officials immediately respond to telephone messages...
Yeah, both groups know how to shut up and watch each others backs when it all goes f*@$ ways : )
By the way, I thought they ended up using channel B because they did not take the full effect of the Doppler shift for channel A into account. Can anyine correct me on this? ..
FTA: The probe was to transmit data on two channels, A and B, Atkinson said. His Doppler wind experiment was to use Channel A, a very stable frequency.
But the order to activate the receiver, or oscillator, for Channel A was never sent, so the entire mission operated through Channel B, which is less stable, Atkinson said.
I guess it makes it even worse that it was purely a human error.
Lets just hope noone forgets to turn on the anti-missile lasers on the orbiting satellites. Bigger mistakes can happen. :)
Codito, ergo sum.
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
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?
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?
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
The first scientific assessments of Huygens' data were presented during a press conference at ESA head office in Paris on 21 January.
Results include:
You are confusing bad luck with incomptence. it would be bad luck if the system failed when told to activate. It's incomptence if they left the activation codes out of the system. This is a case of the latter, not the former.
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?
...DOH!
But Officer, I DID read the f**king article!
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
Yes, and I'm not sure why we'd have to go to French to get a meaning for D'oh. Homer is English-speaking and "dough" is an English word. Plus it it what doughnuts are made from. I figure since Americans shortened "doughnuts" to "donuts", and Homer is lazy and likes donuts, he just shortened it to "D'oh". (=
It also could be a contraction for "damn, oh!" or preferably "oh damn".
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?
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?
[
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!"
The problem with channel A is not related to the Doppler problem but due to a human error as reported in the article.
See also what I reported on saturday.
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.
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.
You assume that heavily penalizing the person responsible will actually prevent these errors. If this were true, your comment would have some merit. But I believe such a measure would actually be counter-effective. Since the person responsible quite likely did not *plan* this to go wrong, he did not actively deliberate the pro's and con's of such a failure. Therefore the only effect will be even more pressure, with an even larger chance of failure.
Which is, what's the most expensive hardware you've ever ruined?
It's not wasting time, I'm educating myself.
According to this BBC report they've recovered most of the lost data by receiving it directly from the Huygens lander using radio telescopes.
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!
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.