Minor Leak Being Investigated Aboard the ISS

Josh Fink writes "Space.com is reporting that the International Space Station has a minor atmosphere leak. 'An inspection of a vestibule bridging the station's new Harmony connecting module and NASA's Destiny laboratory indicated a slight air leak of about three pounds (1.3 kilograms) per day ..A close-up inspection of the vestibule seal by the station's three-astronaut Expedition 16 crew using an ultrasonic leak detector found no trace of a leak on Wednesday, [NASA spokesperson Lynette Madison] said. Studies of the station's overall internal pressure also found no signs of decay, she added.' While this is yet another technical issue with the ISS, when will this end? I am all for the space program, but there have been some major issues lately."

Comments

Comes with the territory

[SIGALRM]

I am all for the space program, but there have been some major issues lately

Being "for the space program" requires some acceptance of the massive risks inherent in manned space travel. If mechanical systems are design-simplified it may reduce points of failure.

KERMIt, a "Kit for External Repair of Module Impacts", is one of those simple systems being developed at Marshall Research to seal punctures in the ISS. It will enable crewmembers to seal punctures from outside damaged modules that have lost atmospheric pressure. Delivery of the kit is scheduled for next year. KERMIt is also useful for sealing leaking atmospheric seals as TFF article describes (more info here).

Re:Comes with the territory

[iminplaya]

Being "for the space program" requires some acceptance of the massive risks inherent in manned space travel.

You're not kidding. The submitter's complaint is like bitching about the Wright Brother's airplane not being able to fly 100 people across the Atlantic by the end of 1904. The thing is an experiment, ok? Some problems may be due to poor decision making, but I think we can still cut them some slack here. This is not like the Challenger disaster where I believe upper management committed criminal negligence for political expediency. They were warned about that impending failure to the point that the TV news reporters were discussing it before launch. So they got a leak. Use it to ventilate the bathroom.

Re:Comes with the territory

[fahrbot-bot]

KERMIt, a "Kit for External Repair of Module Impacts", is one of those simple systems being developed at Marshall Research to seal punctures in the ISS.

The kit contains foil and a pack of Tropical Fruit Bubbalicious...

Re:Comes with the territory

[Anonymous Coward]

The purpose of the ISS is to learn how to build and maintain large facilities in space. It is a learning process. My question to those that use issues like this as a reason to criticize the ISS is simple: Would you rather have this kind of problem come up on a lunar base where the crew was three days, not two hours from safety? How about on a Mars mission where there was no chance of sending repair parts or rescuing the crew? It is far better to discover issues like this, or the torn solar panel, or the metal shavings they found in an array rotary junction, now and figure out how to deal with it and prevent it from happening again in the wading pool of low Earth orbit rather than in the deep ocean of space.

Re:Comes with the territory

[iminplaya]

"Damn perfectionist." :-)

The Wright brothers weren't spending my tax dollars on their experiments.

Damn! You ARE old.

ultrasonic leak detector?

[Anonymous Monkey]

Just wondering, but did a blue box show up on the IIS?

I Agree!

[Anonymous Coward]

It's like, when I drive to Dallas to Houston I don't have any problems. But when NASA tries to build a space station in orbit stuff goes wrong!

What is up with that?

Re:I Agree!

[Hatta]

I guess you don't have out of state plates then.

"when will it end?"

[taniwha]

hopefully never - the whole point is it's an engineering experiment, if nothing fails they won't learn anything, it'll just be a bunch of guys sitting around wondering what they're doing there

Re:"when will it end?"

[MightyYar]

Besides, learning that something got stuck on the seal before they connected the two segments would hardly be a valuable scientific discovery. That isn't necessarily the case. It would show that their current procedure of ensuring a clean seal is either not good enough, or the seal is not robust enough to handle unavoidable amount of contamination. In either case, it is better to discover this in low earth orbit than on the moon or on Mars.

Going to space is hard

[TooMuchToDo]

While this is yet another technical issue with the ISS, when will this end? I am all for the space program, but there have been some major issues lately."

Going to space is hard. It shouldn't stop us from doing it. Issues will crop up.

Re:Going to space is hard

[afidel]

That and we're doing it on the cheap. Even at the height of the Apollo program we were still spending less as a percentage of GDP on exploration than the Spanish had during Columbus's time or the Persians or Romans had during their time. Americans like to think of ourselves as explorers, but as a nation we really aren't really into funding exploration like many of our predecessors, we're a lot more like China, fairly isolationists with occasional small forays outside.

Re:Going to space is hard

[maxume]

Please compute the ROI for exploring space and say, discovering all that gold that Spain got from the new world. The comparison is a non sequitur.

Problems never end

[YA_Python_dev]

I agree.

While this is yet another technical issue with the ISS, when will this end?

Never. When you build something big, hardware or software, you will have problems. You can't expect to have everything always work the first time.

When you encounter a problem you fix it, it's that simple.

Remember: "The perfect is the enemy of the good." -- Voltaire

Re:Problems never end

[Anonymous Coward]

When you encounter a problem you fix it, it's that simple.

And more importantly, you get better at fixing them. That's really why we're out there after all. We're gaining experience that can only be gained the real way.

Re:Problems never end

[DerekLyons]

When you build something big, hardware or software, you will have problems. You can't expect to have everything always work the first time.

Or even the n th time. A system as large and complex as the ISS will always have problems. Period.

Re:Problems never end

[david.given]

That said I have to wonder if the ISS could be bumped into a lower maintenance orbit and used as a hub for a bolo style rotating space station.

It's too low as it is --- there's enough air resistance that it has to be reboosted at intervals to keep it in orbit. (It has to be that low because otherwise the shuttles can't get there. They have lousy range.) Lowering the orbit any further would be very dangerous.

As for spinning it (you did mean bola, right? Unless you were actually thinking of giant robotic tanks, which I will admit would be quite cool), not only is it not designed for that and would fall apart, but if you want gravity there's plenty on Earth, where it's quite cheap. One of the main purposes for getting into space is to get free fall.

I rather regret that Mir was destroyed for purely political reasons. If the ISS was built as a set of add-on modules to Mir, gradually superseding Mir's own modules as they began to break down, construction could have gone a lot faster. Even if the Mir modules stopped working completely, they'd still have considerable value as salvage.

Rather than a trip to the moon, I would be far more excited to hear about an ISS greenhouse that does all of the air and water maintenance.

I want a balloon. A ten or twenty metre inflatable habitat module, semitransparent hopefully, in which plants a grown. Inflatables and plastics are the future of spaceflight; look at the cool stuff that Bigelow Aerospace are doing. But even they are simply replicating existing modules using inflatables. It ought to be possible to use the new materials to radically change the way space stations are built. How about a 100m wide spherical envelope, full of air, with your space station built inside? Now, that would be cool, particularly once you have a decent amount of plant life in there...

these problems are the reason we need ISS

[Anonymous Coward]

guys... I work for nasa on the space station program... i am amazed at how people frame the detection and fixing of problems on the space station are such a negative thing... the space station construction is so incredibly difficult and complex... and when we have issues, people point them out as never ending. This is the 2nd space station... compare that to the 2nd airplane.

And the biggest thing that amazes me is that these problems are the biggest reason to have the space station!!! We have to learn how to fly in space long term... and fix problems just like these!! what kind of problems do you think we will have when we go to the moon and mars?? do people honestly think if we just drop what we are doing and took off trying to get to mars, we would find out just how much learning we have left to do.

overall, i think the american public is left feeling ashamed of the problems they see on the ISS, instead of being proud of the accomplishment because they don't really comprehend just how insane the Apollo successes were, and how ahead of their time they were. We really do have a lot left to learn about flying in space and fixing things in space with the materials in place, and unless we want to take insane risks and costs like were done in the Apollo program, we need to do that with the space station.

these problems... their detection, isolation, and recovery, are the greatest asset of the space station.

Re:these problems are the reason we need ISS

[Anonymous Coward]

I know you guys are working with a neutered budget, but that doesn't mean they had to pawn off your [shift] key. That was totally lame on their part.

Re:these problems are the reason we need ISS

[stevied]

This is the 2nd space station...

2nd?

Re:these problems are the reason we need ISS

[R3d M3rcury]

Second space station that NASA has been involved with.

Re:these problems are the reason we need ISS

[popo]

I thought I issued a company-wide memo about NASA employees surfing Slashdot during work-hours.

Please come down to my office right away.

pin sized hole hard to reach

[wizardforce]

While this is yet another technical issue with the ISS, when will this end? I am all for the space program, but there have been some major issues lately."

it's probably a leak about the size of a needle hole hidden somewhere out of reach with a simple leak test. it wouldn't need much, 1.3 kg of air is about 1 cubic meter in size leaking over a day's time. considering there's about 10N/cm^2 force and the force exerted by a moving column of air is mv^2 while the density m is 1.28 kg/m^3 solving for the size of a hole required to vent the gas is about 2mm in diameter if back of the envelope calculations are correct [probably not but you get my point]

Re:pin sized hole hard to reach

[kebes]

Sounds about right. I just ran it through some simple effusion equations (kinetic gas laws). Assuming that the amount of air escaping is 1.3 kg (1.14 m^3), and that the volume of the room it is escaping from is ~200 m^3 (apparently the total final size of the ISS is 1000 m^3), and that the ISS is pressurized to 101.3 kPa (the Wikipedia article says that it is), then we can calculate the time for 1/200 of the air (0.5%) to escape, as a function of the hole diameter. It turns out that a hole of diameter 0.15 mm will lead to that kind of rate of pressure loss (1 m^3 in the first day).

Needles to say, the effusion equations have various assumptions built into them, and I had to make all kinds of assumptions about the values... but at least to within order-of-magnitude, this suggests a pinhole-sized leak.


Details for anyone who cares: The effusion equation can be derived similar to the conventional gas law expressions, by calculating the number of molecules per unit area that impinge on a wall section of a certain size (the hole). (We assume a container in vacuum, so that any molecule that impinges on the hole is lost irreversibly to the outside.) The equation, as you might expect, turn out to be exponential decays (since the derivation incorporates the decreasing internal pressure as air is lost):

N(t)/N_total = exp( -(A/V)*sqrt(k*T/2*pi*m)*t )

or

t = ( -(V/A)*sqrt(2*pi*m/k*T) )*ln(N(t)/N_total)

where:
t, time (until the given loss of atmosphere)
V, volume of container
A, surface area of hole
m, mass of gas molecules
T, temperature (~300 K for room temperature)
k, Boltzmann constant
N(t), # molecules at time t
N_total, total # molecules (initial quantity)

Re:pin sized hole hard to reach

[megaditto]

Your formulas are a good first approximation. However, since we are not dealing with a fluid here, they don't work very well (plus I think you mixed up your numerator/denominator somewhere in there).

Anyways, I am sorry for not being very clear in my previous post.

Here is the reasoning: number of molecules that escape depend on the opening area, the time, and the number of collisons. The collisions depend on the pressure, temperature, and the molecular mass only (the formula is p * sqrt(1/(2 k T m)) where P is pressure, k is Boltz. const., T is the abs temp in K, m is the molecular mass).

The final formula looks like:
M_lost=A * time * p * m * sqrt (1/(2 * k * T * m ))

finally, the two m's cancel and you get
M_lost=A * time * p * sqrt (m/(2 * k * T))

Now, M_lost is 1.3
p is 10^5
m is 29 (for air)
k is 8.3
T is 300

Re:pin sized hole hard to reach

[bishop32x]

I think you're confusing liquid and fluid. A fluid is a substance which is unable to resist any shear stress, and all gases exhibit this behavior. Also, your units seem to be off, if the molecular mass is dimensionless then you're missing a mass^.5 somewhere. If not then you need to account for moles and the fact that m= .029 kg/mol.

Gotta take a leak

[Anonymous Coward]

where are those astronaut diapers when ya need them?/

Cues

[Bearpaw]

Cue human missions vs automated missions debate.

Cue government space programs vs private space programs debate.

(At least the breathing oxygen vs breathing vacuum debate would be short.)

Space is hard

[geekoid]

but to quote some guy:
"We choose to go to the moon. We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win, and the others, too." - JFK

http://www.quotesandsayings.com/sjfk.htm

Yeah, it's hard and complex. We will learn how to make maintenance of those systems routine and automated. We will continue to look forward, we must less we stagnate and die. The fate of the Dinosaurs will be our fate as well if we don't diversify off this rock. There are a lot of steps between here and the next habitable planet. Whether it's habitable because nature forms more planets like ours, or habitable because we terrorformed it makes no matter.

Pound != 0.454 Kilogram on the ISS

[corsec67]

FTA: "a slight air leak of about three pounds (1.3 kilograms) per day".
I hate to break it to this reporter, but on the ISS, a pound is a large number of kilograms, since they are in microgravity. Pound is a unit of weight, and gram is a unit of mass. The conversion between them depends on the gravity that the object is experiencing, which in this case is almost none, so the 1.3 kilograms of air is almost 0 pounds.

Too bad we can't moderate the TLP as "troll".

[mmell]

After all, Columbus, DeGama, Balboa, Cortez, Magellan - they all had flawless journeys of exploration, didn't they?

End debate

[geekoid]

"Cue human missions vs automated missions debate."
Both.

"Cue government space programs vs private space programs debate."
Government for pushing new boundaries, private for established routine stuff.

"
(At least the breathing oxygen vs breathing vacuum debate would be short.)"
I can't weigh in on this one because I couldn't hear what the guy in vacuum was saying...

Re:3 lbs a day!?

[wizardforce]

air has a density of about 1.28 kilograms per cubic meter so 1.3 kilograms of air occupies a space just over 1 cubic meter in size, in this case it is 35.9 cubic feet of air to be exact. The fact it has some easily measurable density allows for helium balloons to remain in the air as well as airplanes to shuffle large amounts of air around to create significant lift. the amount of energy air turbines generate depends on the density of air being as high as it is otherwise the airspeed required to produce any amount of power would be much higher if the density were lower.

Movie-inspired salvation

[Lurker2288]

I totally saw this in a movie once. All they need to do is open a prominently featured can of Dr. Pepper and let the soda spraying out through the hull show them where the leak is. Caveat: this plan carries a small risk of vaccuum-freezing Tim Robbins.

Re:Movie-inspired salvation

[Anonymous Coward]

I don't get it. What's the caveat?

Let's give up on all research.

[palegray.net]

Quoth the poster: While this is yet another technical issue with the ISS, when will this end? I am all for the space program, but there have been some major issues lately.

Yet another round of bugs were discovered in several major operating systems and userland packages. I'm all for operating systems, user software, and advances in computing technology. but there have been some major issues lately. I vote we give up and go back to the abacus and using smoke signals to communicate.

Re:Pound != 0.454 Kilogram on the ISS

[Anonymous Coward]

You sir are technically correct. The best kind of correct.

Re:Pound != 0.454 Kilogram on the ISS

[turgid]

Pound is a unit of weight, and gram is a unit of mass.

My dad, who is from the Olden Days when people used pounds and inches, and an Engineer, says that there exists a "pound-mass" and a "pound-force" and the reader is expected to have the wit, depending on context, to distinguish between them.

Even More Informative!!

[JLDohm]

According to the ever reliable Wikipedia, a pound is defined to be 453.59237 grams (pound(mass)), OR 4.4482216152605 newtons (pound(force)).
We'll give them the benefit of the doubt and assume that the ISS isn't completely devoid of air.

Re:Mod parent up!

[MichaelSmith]

Thats pounds mass. Gas quantities were measured that way all through the Apollo program.

Re:Pound != 0.454 Kilogram on the ISS

[Detritus]

It's about 0.1 slugs of air per day, or 6.6 stone per fortnight. Are you happy now?

failure is not an option?

[sohp]

Seriously, the story of the space program is not "we did so well nothing went wrong" but, "when things went wrong we used our guts and brains and fixed them"

Examples:

Gemini 8 thruster stuck. Armstrong was able to regain control and return safely home.
Apollo 11 landing 1201 and 1202 program alarms. Programmers on the ground and flight engineers were able to rapidly determine that the alarms posed no threat and the landing continued to success.
Apollo 13. Catastrophic explosion disabled the service module. The astronauts returned home safely using the LEM as a lifeboat and some creative navigation.
Skylab launch: Ripped off a solar panel and part of the outer skin. Astronauts were able to rig a replacement screen to cool inside of the lab and open the other solar panel that was stuck partly open. Three expeditions extended the time in space records and recorded what was then the most detail solar observations ever.
STS-49: Multiple attempts to capture and return an Intelsat satellite failed, but a final attempt involving the shuttle commander flying directly to the satellite and it being hand-captured by 3 spacewalkers succeeded.

There are plenty more, including the recent working solving problems with stuck and torn solar panels.

Incidentally, these kinds of things are why I favor human spaceflight over robots for complex and difficult challenges.

Re:3 lbs a day!?

[j79zlr]

While this may sound funny, but isn't that a lot. While air does have weight how much air is 3 lbs? The area over vermont 10' deep?

If you took an invisible column and surrounded the Eiffel Tower, the air inside that column would weigh more than the steel structure.

Idiot OP?

[dotancohen]

While this is yet another technical issue with the ISS, when will this end? I am all for the space program, but there have been some major issues lately. Are you kidding? Do you not have any idea how fucking complex and unique the ISS is? My 2008 Ford Focus has gone in for repairs three times in the four months that I've owned it, and Ford has been building those motherfuckers for over 100 years now. The ISS is the third of it's kind, designed and built from scratch and completely hand made. In space! By people wearing spacesuits! You don't expect a problem every now and then?!? I'd go so far as to say that problems are the major mission of the ISS. The creation and solving of problems is building experience for NASA, the Russians, the Europeans, and everybody else involved. Not to mention those brave guys up there actually manning the thing. Problems or not, the ISS is one hell of an achievement. The fact that it hasn't killed anybody yet is either a miracle or testimony to the amazing engineering that has been invested in it.

Not to worry....

[Radical Moderate]

Once the air level drops below the hole, they'll fix it no problem.

It's a minor leak, but it's very expensive air

[Phat_Tony]

At $20,000 per pound to deliver more air with the space shuttle, it's very expensive air their losing, at $60,000 worth of air per day. How long would it take to leak a minor scientific research project out of the budget?

Seriously?

[cybersavior]

Of course there's gonna be problems. Imagine if in the 1400's the entire would could see in real time every splintered mast, frayed rope, broken rudder, or lost anchor on columbus' voyage. Expect this kind of stuff in the exploration of a region un-mastered by man.