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New Sensor Finds Leaks in Spacecraft

Roland Piquepaille writes "With financial support from NASA, Iowa State University (ISU) engineers have developed a sensor to quickly find leaks in a spacecraft. This sensor locates an air leak by listening to the noise generated by the air rushing out of the leak and includes an array of 64 elements that detects vibrations as they radiate along the spacecraft. Because astronauts cannot hear the noise caused by escaping air, NASA needed to design a system to help them. As one ISU researcher said, 'NASA wants to be able to find these leaks. Fixing them is easy. But the question is, "Where is the leak?"' Now that this sensor has successfully been tested on the ground, NASA is evaluating a proposal to build a prototype of the leak detection system for future missions.

115 comments

  1. Another application. by GreggBz · · Score: 4, Funny

    It's also good for "who farted."

    1. Re:Another application. by Anonymous Coward · · Score: 0

      Actually, the HWSIDI sensor is far more efficient for that purpose.

    2. Re:Another application. by mikael · · Score: 1

      It's also good for "who farted."

      We just place lots of carbon dioxide and methane detector strips on all the walls and chairs.

      --
      Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
    3. Re:Another application. by davidsyes · · Score: 1

      In SPACE, no one can year you STREAM...

      --
      Previously: "Linux... Toward the Sunrise..." Now: "Linux... Toward the-- No, now, part of Every Sunrise"
  2. If it find leaks... by Dr.+Spork · · Score: 4, Funny

    First customer: Steve Jobs

    1. Re:If it find leaks... by bheekling · · Score: 1

      Second customer: Mozilla Firefox

      --
      "..."
  3. Just use Pepsi by Anonymous Coward · · Score: 0

    I saw it in a movie once.

    1. Re:Just use Pepsi by khallow · · Score: 1

      I was thinking the same thing except that it was Dr. Pepper. This is a solved problem. Hmmm, that reminds me, we need to move all biological research to space where advanced DNA modeling with M&M's can occur.

    2. Re:Just use Pepsi by Anonymous Coward · · Score: 0

      My favorite line from that stupid, stupid movie: "That looks like human DNA."

    3. Re:Just use Pepsi by khallow · · Score: 1

      I don't know if it's incompetence, a preexisting medical condition (like de Palma being totally nuts), or vengence on a meddling Disney corporation that is responsible for Mission to Mars. But product placement is so obvious in the movie (only a minute long informercial on the joys of M&Ms or Dr. Pepper would be more so), that I think Disney must have really ticked de Palma off. Hmmm, glancing at this interview, I see two lines really stand out:

      On March 9 [the movie was released a day later - khallow], Mr. De Palma contacted me, saying that because current U.S. press junkets are only exploitative publicity events, he would like to offer this site the first -- and possibly only -- American interview for the film.

      and something de Palma says in the interview

      Well, I thought it was a little insane, the date. I thought we should try to beat out the other Mars movie, but during the year that we were making the film, the other one automatically fell way behind us. But the studio locked into this March 10 date and just never moved off it. And my attitude was, "Guys, you want it March 10, you're gonna get it March 10!"

      So he gives only one interview supposedly in the US (strange thing for a director to do) and the only thing (as far as I saw) that he says about his studio backers is that they wanted it done on a tight schedule and he delivered. Also a lot of talking about "storyboarding" (laying out a series of stills ahead of time that you want in a film sequence) and how he had to follow it.

  4. How clever research proposals are rewarded ... by foobsr · · Score: 1

    National Aeronautics and Space Administration - Small Business Technology Transfer (STTR) Program

    PROPOSAL NUMBER: 06 T5.02-9832

    Have a try :)

    CC.

    --
    TaijiQuan (Huang, 5 loosenings)
    1. Re:How clever research proposals are rewarded ... by Anonymous Coward · · Score: 0

      I have a proposal for a leaky spacecraft that they can test this on!

  5. Get yer bag, we're going to Mars... by Digital+Nobody · · Score: 0

    All this new spaceship tech, or spaceship related tech really gets me wondering why now... I think we've got our collective eyes set on a destination, and for whatever reason, it just became critical...

    --
    Penguin walks into a bar and asks the barman; Has my father been in here? The barman says; Dunno what's he look like?
  6. This would have been nice... by apdyck · · Score: 1

    I bet NASA is wishing they had this ten years ago!

    --
    .sig
    1. Re:This would have been nice... by sykopomp · · Score: 1

      !funny

  7. Summary Incorrect by blues_shuffle · · Score: 1, Informative

    The summary states that the detection system detects the sound made by air escaping. This is not true. The sound of the air escaping is OUTSIDE the spaceship (as said in the article) and therefore cannot be detected within the craft. The detection system is simply the array of vibration sensors.

    1. Re:Summary Incorrect by WillRobinson · · Score: 1

      Sorry, but wrong, the ship will be vibrating at the source of the leak. Therefore if you have several sensors around you should be able to triangulate the position pretty accurately.

    2. Re:Summary Incorrect by Hoi+Polloi · · Score: 1

      They must be able to tell the difference between the vibrations from escaping air vs those caused by the multitudes of systems running like A/C, ventilation, etc. Maybe they turn them off briefly to remove background noise and vibrations before searching for leaks.

      --
      It is by the juice of the coffee bean that thoughts acquire speed, the teeth acquire stains. The stains become a warning
    3. Re:Summary Incorrect by Dunbal · · Score: 1

      Sorry, but wrong, the ship will be vibrating at the source of the leak.

            But not for very long, depending on the size of the leak.

            "Hey look we have a leak in section 2, the sensors have - oh, no, it's fine now..." :)

      --
      Seven puppies were harmed during the making of this post.
    4. Re:Summary Incorrect by WillRobinson · · Score: 1

      Yes, their ultrasonic. And stay at the same frequency, unless the hole changes in size. The same technology is used to detect holes in environmental suites, and electric lines leaking.

    5. Re:Summary Incorrect by rts008 · · Score: 1

      And your ears are not vibration senors? Hmmm...methinks you may need some remedial education on this one.

      Sound is nothing more complicated than the brain's reacting to specific nerve impulses from the auditory nerves due to vibrations affecting cilia (all 'tuned' to respond to specific frequencies of vibration-like piano strings) that are attached to these aforementioned nerves.
      Basically, sound is all in your head...outside of your head it's all just vibrations of varying frequencies.

      --
      Down With Slashdot BETA!!! I've been around the corner and seen the oliphant; you can only abuse me from your perspecti
  8. Which brings up a related question by LM741N · · Score: 1

    What in the world do they do for human air leaks- I mean passing putrid gas on the spaceship?

    1. Re:Which brings up a related question by Zymergy · · Score: 1

      One Word: Beano http://www.beanogas.com/ ...Being sealed inside a space capsule would give a whole new take on the ol' "Dutch Oven" treatment wouldn't it?

    2. Re:Which brings up a related question by Hoi+Polloi · · Score: 1

      NASA is working on spaceship-safe matches for that.

      --
      It is by the juice of the coffee bean that thoughts acquire speed, the teeth acquire stains. The stains become a warning
    3. Re:Which brings up a related question by ChrisA90278 · · Score: 1

      Long before there were manned spacecraft there were submarines and diving suits. Both of these were in use just after the turn of the last century (early 1900s) Answer is Either "open curcuit" new air pushes old air overboard or "closed" where air is recirculated through dehumidifiers and carbon filters and many times also through hydroxide "scrubbers" to remove carbon dioxide. So by 1960 these was half a century of technology for them to draw on.

  9. Re:In space by AP2k · · Score: 1

    Hmmmm, I have a mass of air leaking from a space ship. My detector mechanism is outside in the vacuum. I wonder how I could detect this escaping air? Maybe the detector will announce that it hears something when it passes through the mass of air? BRILLIANT!

    Now where's my contract?

  10. The reason these things cost so much by Anonymous Coward · · Score: 0

    ...evaluating a proposal to build a prototype...

  11. Auto Patch by mdarksbane · · Score: 2, Interesting

    I'm curious what size of leak they're targetting here.

    I've heard an interesting suggestion for an automatic leak plugging system - floating, easily popped bags of quick drying sealent. Any leak will create air currents that will suck the bags into the holes, where they pop and seal the whole.

    This of course ignores all sorts of potential problems (holes in areas obscured by cables/ductwork, for one thing) but I thought it was neat anyway :)

    1. Re:Auto Patch by GIL_Dude · · Score: 0, Redundant

      Yep, Robert Heinlein had those in his novels many a year ago. Seems like they could work. If they don't work due to the weight of the sealant then they could at least be used without sealant and they would still show where the leak is.

    2. Re:Auto Patch by Hoi+Polloi · · Score: 1

      Judging from the article it looks like they are after pinhole sized holes from micrometeorites. I assume a hole that size would create a slow leak that wouldn't be obvious. Big holes would be easy to detect because the astronaut's eyes would pop out "Total Recall" style.

      --
      It is by the juice of the coffee bean that thoughts acquire speed, the teeth acquire stains. The stains become a warning
    3. Re:Auto Patch by imsabbel · · Score: 2, Informative

      think of small leaks..
      They can be viciously hard to dedect, hat lose tons of air over a larger timeframe (and air isnt really replaceable up there).

      I work with vaccum chambers, where the same problem can happen (just inverted). And even having a rather good access to all parts, it can be terrible hard to find a leak without disassembling parts of the chamber. (Thats the reason you use helium and a mass spectrometer for leaktesting. Just hose down the thing and check where helium seeps through...)

      --
      HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
    4. Re:Auto Patch by rah1420 · · Score: 1

      Yep, Robert Heinlein had those sealant bags] in his novels many a year ago.

      ISTR he also write a (short) story where someone sat on a leak to plug it. Froze his butt cheek right up, it did, till the rescue team arrived.

      --
      Mit der Dummheit kämpfen Götter selbst vergebens.
    5. Re:Auto Patch by amRadioHed · · Score: 1

      Neat idea, except for the fact that it will also plug up useful things like air filters, vents, and lungs. It seems like getting rid of all air on the spacecraft would be just as effective.

      --
      We hope your rules and wisdom choke you / Now we are one in everlasting peace
    6. Re:Auto Patch by amRadioHed · · Score: 1

      obSimpsons:

      Lisa: I think it's ironic that dad saved the day while a slimmer man would have fallen to his doom.
      Bart: And I think it's ironic that for once dad's butt prevented the release of toxic gas-

      --
      We hope your rules and wisdom choke you / Now we are one in everlasting peace
    7. Re:Auto Patch by andphi · · Score: 1

      You remember correctly. I can't recall the name of the story just now, but I've read it in the last month or so. I think it was in "Green Hills of Earth"

    8. Re:Auto Patch by Chris+Mattern · · Score: 1

      It was called, what else, "Gentlemen, Be Seated!".

      Chris Mattern

    9. Re:Auto Patch by HaloZero · · Score: 1

      In the movie "Mission to Mars", Gary Sinise's character McConnell used a squirt-bag of Dr. Pepper to locate the leak in their aircraft. Just having something airborne to show the 'funnel effect' of the sucking would be invaluable. Plus, it doesn't really matter how big the hole is. The soda's going to vent itself, regardless of the size of the breach.

      --
      Informatus Technologicus
    10. Re:Auto Patch by mobby_6kl · · Score: 1
      Nope :)

      I've read a few of Heinlein's short stories recently, so after a quick memory refreshment I can say that the "Green Hills of Earth" is not the story in question (it's about Rhysling, the Blind Singer of the Spaceways).

      "Gentlemen, Be Seated!" is the one where they plug a leak in the moon tunnel by sitting on it:

      I tore of my own trousers, had a panicky time before I found the exact spot in the dark, and set down on it, with my right buttock pressed firmly against the opening. It grabbed me like a suction cup, icy cold. Then it was fire spreading through my flesh. After a time I couldn't feel anything at all, except a dull ache and coldness.
    11. Re:Auto Patch by andphi · · Score: 1

      Ah. I see the confusion. The story containing the butt-seal is in the book entitled "Green Hills of Earth" but not in the story which gives the book its name. We're both right.

    12. Re:Auto Patch by Cragen · · Score: 1

      Is that the story where the spaceship used ping-ping balls to locate leaks?

  12. Re:In space by Anonymous Coward · · Score: 0

    What hat size are your underpants?

  13. Not exactly new technology by Teun · · Score: 2, Informative

    This type of survey has been used in the oil industry since the 1980's...

    "noise log" leak detection

    But I have to admit this is 3D against 2D.

    --
    "The likes of Facebook and WhatsApp are free to those whose privacy is of zero value."
  14. Re:In space by Anonymous Coward · · Score: 0

    You can't have an air leak if there's no air. You're either a normal moron or a moron with who can't write a joke.

  15. Re:In space by Anonymous Coward · · Score: 0

    Assuming you aren't joking...

    If you RTFA you'd notice that the monitoring device is INSIDE the craft. If there is no air left in the vessel to transmit sound then you'll know because the astronauts will be floating corpses.

  16. KISS by Tank · · Score: 5, Funny

    I love tech as much as the next guy, but why not keep it simple... Submerge the craft in water, and look for bubbles. :D

    1. Re:KISS by PitaBred · · Score: 0, Redundant

      As big as the shuttle is? It's built for negative pressure, not positive pressure. I mean, the orbiter is 56' tall on the runway. Remove some height for the tail and the landing gear, that's still a good 20' deep to submerge the entire thing, which makes the outside pressure somewhere around 1.6 atmospheres. But I'm guessing you meant this as a joke. I just wanted to throw some random facts out to make myself look relevant, even though I'm not ;)

    2. Re:KISS by confused_demon · · Score: 1

      I'm probably gonna butcher the quote, but in futurama, when they goto the ancient lost city of Atlanta: Fry: How many atmospheres can the ship take? Prof: Well, given that it's a space ship, some where between 0 and 1.

    3. Re:KISS by jabber · · Score: 3, Funny

      Sure, but the cost of shipping all that water into orbit is prohibitive, and who has time to go around melting comets?

      --

      -- What you do today will cost you a day of your life.
    4. Re:KISS by Anonymous Coward · · Score: 0

      I love tech as much as the next guy, but why not keep it simple... Submerge the craft in water, and look for bubbles. :D

      Yeah that'll work REAL GOOD in outer space!

      mcgrew

    5. Re:KISS by andy_t_roo · · Score: 1

      not to mention the fun and games it would take to keep the side in shadow from freezing solid, and the side in the sun from boiling

    6. Re:KISS by Maelwryth · · Score: 1

      One can only hope they are not triangulating the screams of the astronauts.

      --
      I reserve the write to mangle english.
    7. Re:KISS by Wite_Noiz · · Score: 2, Funny

      Professor Farnsworth: Dear Lord, that's over 150 atmospheres of pressure.
      Fry: How many atmospheres can this ship withstand?
      Professor Farnsworth: Well it's a spaceship, so I'd say anywhere between zero and one.

    8. Re:KISS by greedyturtle · · Score: 1

      That's just crazy.

      You don't need to submerge the craft, which would require too much water, and a place to put it in. (The ocean won't work.) All you gotta do is put the water IN the spacecraft and watch for the water to spray OUT! The ship contains the water, and you only need enough to fill up the ship.

      You can even use dowsing rods to find where it's coming out.

  17. that's not the only thing it'll detect by Anonymous Coward · · Score: 0

    that's the sound of a million dollars leaking out by the second

  18. Hippy Solution: by Penguinshit · · Score: 2, Funny

    Incense.

    Just follow the smoke... Good for karma and centering your Qi, too!

    1. Re:Hippy Solution: by Carbon016 · · Score: 2, Insightful

      "Our oxygen levels are way too low, what's going on, do we have a leak?" "Chill out guys, I'm just burning some incense, my spirit guide said we'll make it to the moon without oxygen anyway using the power of our minds." Sorry, I just thought the irony of burning oxygen to find an air leak intensely ironic.

    2. Re:Hippy Solution: by v1 · · Score: 1

      Although technically that works very well, there are two basic problems with using smoke

      1) since this is a sealed environment, there are compact air filtration, circulation, and other "life support" systems moving the air around. I'd bet if you lit a stick in the ISS it would immediately fall into an "air highway" in the chamber and beeline for the nearest air filter/recirculation intake.

      2) somewhat related to (1), they have to filter their air because there's no fresh outside the window to air the place out. So they don't pollute the air inside if they can at all avoid it. Unless filtered out, (and I bet right quick too) the place would reek of incense really quickly, and would NOT go away given time like it does in your house. Also those filters are expensive both in cost and transport. (I'd be interested to see what NASA has figured as the end cost for some things like air filters, air canisters, heck, all sorts of things... even small items like screws, tape, pencils, etc - just try to imagine how much it costs them to send up a new ball point pen?)

      --
      I work for the Department of Redundancy Department.
  19. Been around since 1955 or so by Ancient_Hacker · · Score: 2, Informative
    Ultrasonic leak detectors have been around since at least as far back as 1955.

    The telephone company (way back when there was just ONE big one, ATT), used to have like lots of copper wires running from pole to pole (way back when there were wires, and poles, and above-ground stringing).

    In the wetter climates the wires were covered in a lead casing (back when lead wasn't so despised). The lead "tubes" were pressurized to keep the moisture out. If the lead sheathing got a leak, a guy (back when telephone company people in the field were guys) would walk down the street holding up an ultrasonic microphone.

    A little box on his belt would map the ultrasonic frequencies down to the audible range and feed it to his headphones (back when headphones were big clunky black bakelite things).

    1. Re:Been around since 1955 or so by Anonymous Coward · · Score: 0

      Yeah, and NASA has had ultrasonic leak detectors since, oh, Skylab for sure. Point of this is that it explicitly *isn't* an ultrasonic leak detector. RTFA.

    2. Re:Been around since 1955 or so by gnuman99 · · Score: 1

      This isn't a ultrasonic microphone. It locates leaks by structure vibrations, NOT air vibrations. Kinda different.

  20. Inspacenoonecanhearyouscream by Overzeetop · · Score: 0, Redundant

    Oh, come on, you don't get an opportunity like this every day!

    --
    Is it just my observation, or are there way too many stupid people in the world?
  21. Re:In space by confused_demon · · Score: 1
    But in Anime, explosions in space are louder because there's no air to get in the way.

    Seriously though, I kinda hope that this is intended to be used from inside the crew cabin. Using it outside the space craft is gonna be problematic if it actually relies on the sound of the gas escaping.

  22. In The Shadow Of The ISS by OhEd · · Score: 1

    When asked for comment, Buzz Aldrin said "I don't find leaks, I only take them"

  23. No balloons then? by iamacat · · Score: 1

    I thought you were supposed to put some in space ship and check for a leak if they congregate in one place?

  24. Re:Russians Are Better... by burni · · Score: 3, Informative

    Well in this case the simple solution might not be the best,
    because you will hardly see smoke moving towards the leak,
    and when you see you should run ;)

    Think of the ISS it's constructed from cylindrical elements, and you have a quadratic shaped interior, so the space gap is filled with computers (some Laptops == fan) possible cooled instrument racks which emmit heat (convection) and on the inner layer an insulation.

    If your presure- and ultrasoundsensors detect such a leak you have to generate
    smoke, this smoke will going to follow the airflow which is driven by presure diferences,
    but you also have temperaturdifferences or forced convection nearly everywere,
    even the astronauts moving will disturb the free flow extremly, and you have no
    gravition which helps you to settle the turbulences fast.

    The leak might be so tiny, so the volume flowing through it will not interfere with the inside
    atmosphere in deep.

  25. Re:In space by DigitalReverend · · Score: 1

    Finally sound is still transmitted through the material of the spacecraft itself, so monitors attached to said spacecraft would still detect sound. An example of this would be Tonto putting his ear to the ground to determine how big the posse is.

    --
    I read Slashdot for the headlines, because the headlines, unlike the articles, are usually original and never duplicated
  26. In Space No One Can Hear You Scream by Doc+Ruby · · Score: 3, Funny

    They can't mount this sensor outside the craft pointing in, because the intervening empty space carries no sound energy.

    But if they mount it internally, it could find not only leaks, but also target where that hideous alien creature is hiding after it's eaten the ship's cat.

    --

    --
    make install -not war

    1. Re:In Space No One Can Hear You Scream by v1 · · Score: 1

      on the surface that appears sensible, but remember that ANY atmosphere can conduct sound energy. Even a very small leak. A little whisp of gas flowing out of a pinprick of a hole/crack technically conveys sound energy, as the motion of the gas flowing away from the hole. Detecting that is no different than detecting any other sound, it's just that you lose 50% of the sound energy. (because there is only expansion, no contraction) Also considering the very low pressure atmosphere outside such a leak, (there is an atmosphere, even if only 0.00001 A, as a result of the leak) the energy does not transfer well and is very weak compared to the potential sound energy propogated through a dense atmosphere like inside. Also the sound waves quickly lose their conductive media considering how fast they travel relative to the speed of the gas escaping.

      --
      I work for the Department of Redundancy Department.
    2. Re:In Space No One Can Hear You Scream by Doc+Ruby · · Score: 2, Interesting

      But only if there's enough gas to form a medium between the leak and the detector. Unless the entire surface is coated with the detector, then small leaks (with serious consequences over time) can't be detected. And coating with a sensor could use much cheaper and simpler tech.

      --

      --
      make install -not war

    3. Re:In Space No One Can Hear You Scream by hcdejong · · Score: 1

      AIU, gas isn't the medium used. This system measures vibrations (sound waves) traveling through the skin of the spaceship.

    4. Re:In Space No One Can Hear You Scream by Doc+Ruby · · Score: 1

      What's "AIU"?

      We're talking about a scenario where the sensor is mounted outside, not integrated with, the ship. In that case, the only possible medium is the escaping gas, which isn't enough to conduct sound everywhere outside the ship. The inside mounting was treated completely in an earlier message in this thread.

      --

      --
      make install -not war

    5. Re:In Space No One Can Hear You Scream by hcdejong · · Score: 1

      AIU = As I Understand

  27. Beats the old method... by Anonymous Coward · · Score: 0

    *GASP* I'm having trouble... Control... this ... iss.......

    --END CARRIER--

    1. Re:Beats the old method... by Ajehals · · Score: 2, Funny

      Ground control to Major Tom:
      Your circuit's dead,
      there's something wrong.
      Can you hear me Major Tom....?

  28. Do it the way Tim Robbins did it by Anonymous Coward · · Score: 0

    Squeeze out a Dr. Pepper and watch where the drops of liquid go.

    (What? You are telling me that that movie wasn't realistic?)

  29. Don't Tell by Herkum01 · · Score: 0, Troll

    Don't Tell GWB, he will use it on our federal agencies instead!

  30. soap by FranTaylor · · Score: 1

    I find leaks in my bicycle tubes with soap and water. Why don't they spray soap all over it and look for the bubbles?

    1. Re:soap by TomorrowPlusX · · Score: 1

      How do you propose spraying soap on the *outside* of a freaking space ship?

      --

      lorem ipsum, dolor sit amet
    2. Re:soap by flyingfsck · · Score: 2, Insightful

      Because in vacuum water boils and bubbles all on its own.

      --
      Excuse me, but please get off my Pennisetum Clandestinum, eh!
    3. Re:soap by FranTaylor · · Score: 1

      1. It's so low tech it's funny. Come on.
      2. NASA has shown repeatedly that they can invent anything they want to. Have you checked out that insulating ceramic stuff? It's still amazing 30 years later.

    4. Re:soap by Anonymous Coward · · Score: 0

      How do you propose spraying soap on the *outside* of a freaking space ship?

      Maybe they could do it on an upcoming space walk^H^H^H^H^H^H^H^H^H^HEVA.

  31. Re:The obvious... by sqrt(2) · · Score: 1

    Pretty sure this thing works by detecting the vibrations resonating throughout the structure of the ISS, not through the air inside it. So it'll still work, even in a vacuum.

    --
    If you build it, nerds will come. Soylentnews.org
  32. Mission to Mars by vjmurphy · · Score: 1

    In "Mission to Mars" they used Dr Pepper. It has an added advantage in that you can drink it if there are no leaks. This would help keep the astronauts awake, so they are more aware of air leaks. Solves multiple problems.

    --
    Vincent J. Murphy
    Spandex Justice
  33. Obscure references FTW! by Eponymous+Bastard · · Score: 1

    Gil "the ARM" Hamilton doesn't have this problem.

  34. Re:In space by wizardforce · · Score: 1

    there is no air in space but the spacecraft its self can transit "sound waves" they're called vibrations. they don't need air.

    --
    Sigs are too short to say anything truly profound so read the above post instead.
  35. A few clarifications by Anonymous Coward · · Score: 5, Informative

    As one of the principal developers of this technique, I can clarify a few points:

    1. 99% of the leak noise escapes into the vacuum on the downstream side of the leak. Thus conventional industrial leak detection devices are much less effective for leaks into vacuum than for leaks into air.

    2. The real challenge is the extraction of the leak noise from other noise sources. We do this by recording cross-correlations of noise measured at different locations. Electronic (preamp) noise does not correlate and is rejected. Thus we can get far higher sensitivity than a single sensor.

    3. This device uses a piezo sensor with an array of multiplexed electrodes to sense the direction of sound propagation under the sensor. A 3D time-x-y Fourier transform maps the measured correlations from the time/space domain to the frequency/wavevector domain. The wavevector points precisely away from the leak, allowing us to find the leak through triangulation from two or more sensor arrays.

    4. For all you Linux fans, this sensor was developed entirely using open-source software. We used Linux with gEDA schematic capture and pcb.sourceforge.net for board layout. Lab measurements are done using the soon-to-be-published open-source Dataguzzler software on Linux x64.

    (Contact me for more information about Dataguzzler)

    5. One paper on this sensor, published in the journal Ultrasonics, vol 45 (2006) pp 121-126,
    can be found at http://thermal.cnde.iastate.edu/~sdh4/home/leakarray.pdf

              Stephen D. Holland
              Assistant Professor, Iowa State University

    1. Re:A few clarifications by Anonymous Coward · · Score: 0

      I see. So it's magic eh? Kinda like a stud finder?

    2. Re:A few clarifications by ColaMan · · Score: 1

      Bitchin.

      That's all I have to say.

      --

      You are in a twisty maze of processor lines, all alike.
      There is a lot of hype here.
    3. Re:A few clarifications by rvandam · · Score: 1

      I have to say I'm impressed, and that's just with the parts I actually understood. But several people have brought up the Hollywood version of leak detection by introducing something (balloons, Dr. Pepper, smoke, etc) into the air that would then be pulled via air currents to the hole. In one particularly dramatic movie, the liquid then forms a giant icy soda spike sticking out of the spacecraft so that it could be identify from outside and patched.

      Since it was a movie I almost have to assume it wouldn't work but why is that? Is the suction so minimal that normal internal turbulence would disrupt any flow of air toward the leak that might otherwise draw the indicator?

      --
      My religion is better than yours is.
  36. how it works by Anonymous Coward · · Score: 1, Interesting

    I saw a fairly lengthy presentation on this a while back so I have a rough understanding on how it works. It's an array of accelerometers which measures the vibration of the material it's mounted on and then uses software to "triangluate" (wrong word, right idea) the direction and distance from the sensor is to where the "sound" is coming from. There isn't an exact point, more like a probability distribution with hot-spots.

    1. Re:how it works by Anonymous Coward · · Score: 0

      Right word. One sensor picks up a direction; two sensors triangulate. All you need is a direction, not a distance.

  37. Air is not the only sound-carrying medium by w.timmeh · · Score: 2, Informative

    The sound being picked up is not carried by air - it is the vibrations caused by the escaping air transmitted through the spacecraft itself.

  38. can it detect leaks when orbiting Uranus? by Anonymous Coward · · Score: 1, Funny

    otherwise there might be too much methane in the ship

  39. In Space.. by monopole · · Score: 2, Funny

    Nobody can hear you leak! You need machines for that.

  40. So, have they been air conditioning by davidsyes · · Score: 1

    SPACE?

    --
    Previously: "Linux... Toward the Sunrise..." Now: "Linux... Toward the-- No, now, part of Every Sunrise"
  41. So why is this better than... by Anonymous Coward · · Score: 0

    ...having a spaceship/station with a self-sealing hull? Would having a thin layer of some gel-like resin sandwiched inbetween the aluminum or whatever the bulkheads are made of really add that much weight?

    Pinhole leaks would be much less of a problem. At least they'd be narrowed down to where wiring or piping runs protrude through the bulkheads. (And could be something to check for before launch.) Also anything that could cause a leak on a self sealing bulkhead would be much more noticable than a pinhole.

    1. Re:So why is this better than... by Anonymous Coward · · Score: 0

      Perhaps on the next one, but I think retrofitting is the key idea.

  42. Crap idea by EmbeddedJanitor · · Score: 1
    The suction force (for want of a more technical description) of a small air leak is not going to be enough to suck much material around.

    Unless of course the whole atmosphere was filled with tiny flakes of stuff, in which case people would be inhaling them and gooping up their airways.

    --
    Engineering is the art of compromise.
  43. Ames Lab by mkiwi · · Score: 1
    I am a student at ISU and nearly all the research for this type of equipment takes place in Ames Lab (http://www.ameslab.gov)
    I personally know two professors who work there and they are both top-notch.

    -A side note: Ames, IA was the largest producer of Uranium 235 in the world between 1940 and 1950.

    1. Re:Ames Lab by initdeep · · Score: 1

      As a resident of Ames, Iowa, and not a student, I can also say, without a doubt, that ISU is also the leading supplier of bullshit since 1980. :D

  44. "I don't find leaks, I only take them" by Anonymous Coward · · Score: 0

    Surely you were thinking of Alan Shephard ;)

  45. take a leak by peektwice · · Score: 1

    At the risk of being flagged "redundant"...
    So what, now I'm not *supposed* to take a leak in a spacecraft?

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    Other than this text, there is no discernible information contained in this sig.
  46. Old Tech, New Implementation by binaryspiral · · Score: 1

    This type of tech has been in use for twenty years (or more) to find leaks in coolant lines and radiators used in air conditioning systems installed in everything from homes, businesses, and vehicles.

    http://buy1.snapon.com/catalog/item.asp?store=snapon-store&item_ID=68182&group_ID=3201

    With that being said, even with decades of improvements - it's still a tedious task that can be time consuming and prone to false positives. This new implementation with multiple sensors will give the system a much higher success rate in less time - and when you're in an aluminum can a few hundred miles from the nearest breath of air, you want to find the source of your air leak as fast as possible.

  47. Sound in a partial vacuum? by Anonymous Coward · · Score: 0

    Correct me if I'm wrong, but last time I asked, space is a partial vacuum (a UHV, but partial nonetheless). There would be no sound outside the craft, just ejection of air.

  48. Re:In space by v1 · · Score: 1

    uh, what do you think is LEAKING? (hint: "AIR!")

    --
    I work for the Department of Redundancy Department.
  49. Re:In space by v1 · · Score: 1

    "conduct" would be a more appropriate word here than "transmit". Transmit seems to imply something that can be detected from a distance. This is just bolting sensors to the hull like sticking your ear to a water pipe to tell if water's running.

    --
    I work for the Department of Redundancy Department.
  50. Re:In space by wizardforce · · Score: 1

    if the effect was limited just to the hull i'd agree, except that there is obviously a supply of air inside the spacecraft. it could be detected from a distance... inside the craft. which in principle could also be used to detect leaks.

    --
    Sigs are too short to say anything truly profound so read the above post instead.
  51. sturdy machine by mr100percent · · Score: 1

    This has got to be some very sturdy equipment. Ever watched a cockpit video of liftoff? Those are some heavy and prolonged vibrations. Think the vibrational sensors will still work to detect such subtle vibrations later after that much shaking for such a long time?

  52. In space no one can hear you fart by amias · · Score: 0

    ...except nasa.

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    [site]