Slashdot Mirror
Space Station Spacewalkers Stymied By Stubborn Bolt
Hugh Pickens writes "Reuters reports that astronauts at the International Space Station ran into problems after removing the station's 100-kg power-switching unit, one of four used in a system that distributes electrical power generated by the station's solar array wings, and were stymied after repeated attempts to attach the new device failed when a bolt jammed, preventing astronauts from hooking it up into the station's power grid. Japanese Astronaut Akihiko Hoshide got the bolt to turn nine times but engineers need 15 turns to secure the power-switching unit. 'We're kind of at a loss of what else we can try,' said astronaut Jack Fischer at NASA's Mission Control Center in Houston after more than an hour of trouble-shooting. 'If you guys have any thoughts or ideas or brilliant schemes on what we can do, let us know.' Hoshide suggested using a tool that provides more force on bolts, but NASA engineers are reluctant to try anything that could make the situation worse and as the spacewalk slipped past seven hours, flight controllers told the astronauts to tether the unit in place, clean up their tools and head back into the station's airlock. NASA officials says the failure to secure the new unit won't disrupt station operations but it will force engineers to carefully distribute electrical power from three operating units to various station systems and says another attempt to install the power distributor could come as early as next week if engineers can figure out what to do with the stubborn bolt. 'We're going to figure it out another day,' says Fischer."
Duct tape?
Just thinking out loud here: how many bolts does it take to hold down the power unit in the first place? If the original plan calls for ten bolts, then one missing bolt would only diminish the strength by 10%.
Clearly they need to oil the threads. Or use anti-seize. Or give the tiny Japanese man a cheater bar. ;)
you're obviously not an engineer. the big things are made up out of tiny things. its always* a tiny things that gets you
I suppose there are no tap and die kits onboard to cut new threads into either the bolt or the module. Should be added to the tool inventory.
Silicon & Charybdis McLuhan Kildall Papert Kay
Sounds like you haven't turned a whole lot of bolts in your day.
Any self-respecting engineer has a can of WD-40 handy for moving stubborn bolts, de-greasing and baiting fish.
WD40
If a bolt will not turn, lubricant is a pretty clear answer...
As for the cheater bar, that's what they were afraid to try because they are probably afraid of snapping the bolt. Bad thing to do in space.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
"Stubborn [Bolt] Stymies Space Station Space[walkers]" ... So close, yet so far away.
Sigh
Unfortunately, there'll be no FTFY coming from here -- move along.
Yesterday's Weirdness is Tomorrow's Reason Why
Common error with multiple fasteners. Loosen the other bolts, then tighten them all evenly.
Simple
Damn those self-sealing stem bolts.
put some soap on it and it will go all the way in :)
Get the oxy acetylene out all any stuck bolt needs is bit of heat.
They should have used self-sealing stem bolts, they don't have this problem.
A squid eating dough in a polyethylene bag is fast and bulbous, got me?
freeze the bolt, heat the fitting
"If you guys have any thoughts or ideas or brilliant schemes on what we can do, let us know."
They're asking Slashdot?!
Just hammer it in with a crescent wrench.. what's the matter with these people?
“He’s not deformed, he’s just drunk!”
Oh, come on, this thing weights zero in orbit, they can just scotch-tape it in place! ;)
Violence is the last refuge of the incompetent. Polar Scope Align for iOS
Sounds like they got the bolt cross threaded.
Just need to back out the bolt, run a thread chaser through to clean up the threads and try again.
And if NASA has an Amazon Prime membership, Amazon will have it delivered to the space station by Wednesday (if they pay the $3.99 overnight delivery fee). There may also be a small surcharge for orbital delivery.
Stubborn Screw Stymies Space Station S-tronauts: so stylish slashdot suggests some of the stylish self-sealing stem sort!
In a vacuum the metal parts, if very well machined, might be trying to bond together. Ball Aerospace used to sell a compound that was designed to keep the door on the Lunar Excursion Module (LEM) from seizing shut in the vacuum of space. They sold it later to coat LP records to reduce friction from the diamond stylus dragging through the groove in a vinyl record. Perhaps they have some of that or moly paste for the threads like used for the spark plug in a gasoline motor with aluminum head threads. Just a thought...
. . . there's always one last bolt that doesn't fit, and too many screws of the wrong size, too few of the right size, a dinky little five-sided hex wrench, and an ancient Egyptian plan for building pyramids written in Hieroglyphics.
NASA needs a gear-head astronaut with NASCAR Hillbilly Armor experience. And a six-pack to offer him, because he will refuse to take pay for such a simple task.
Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
The big question now, if the problem is cross-threading between bolt and threaded bolt-hole, after the bolt has been jammed nine turns, is, can the bolt be removed? Forcing in a cross-thread situation often causes galling, especially in light materials, which causes thread jamming that makes removal require more torque than the cross-threading in required. Removal and check for alignment and thread-fit at first indication of a binding before the normal tightening turn is correct procedure. Especially where extremes of temperature may cause significant expansions and contractions. More especially where original measuring and fitting were done in human environments, at 20 degrees C.
Did you test each individual capacitor in your mid-2000 Dells? If not, shut the fuck up.
Presumably you also test your systems in a vacuum and 300C swings in temperature? Conditions in space are very hard to replicate on the ground and all sorts of weird things happen to metal-on-metal contact in vacuum. The problem here could be (a guess/example) something related to 7% extra torque being needed because of a temperature swing which then bends the male threads slightly, exposing an non-oxidised layer which then vacuum welds to the female thread. Could be a lot of things, and you can't test space technology 100% without, you know, putting it into space.
Please consider this account deleted, I just can't be bothered with the spam anymore.
Mechanical design is very different, I've done both. You're working with analogue systems, which means that everything has a tolerance - let's compare it to 'bits of accuracy'. You can go to a higher accuracy, but it becomes vastly more expensive. Unfortunately, every copy of the component is different, which is scary for CS people. Imagine if every time you created a copy of something, it was *guaranteed* to be slightly different.
So, you suggest doing something like 'unit tests'. Well, that's what they did, and that's what happened here, a unit test failed. They should be getting 15 turns, but are only getting 9. They're not sure why, so they're going to brainstorm and come up with a bunch of possibilities, discount as many as they can based on physics, design etc, and see if they can figure out what's wrong.
Perhaps it would be better if the summary included something like "a unit test failed", then the CS people would understand.
Help I am stuck in a signature factory!
Unscrew, add washers for about 6 turns, rescrew.
you're obviously not an engineer. the big things are made up out of tiny things. its always* a tiny things that gets you
Not a mechanical engineer, no. I'm a network engineer. And when I build a network, I make sure to catch the "low hanging fruit" when I test things.
And when it comes to testing bolts, even with my non-mechanical engineering background, I can see that this is low hanging fruit. Will this bolt be able to turn 15 times in this configuration? I'm sure NASA would have been able to test that in their fish tank, and they probably did; with a different bolt...
Are you seriously saying that you've never tested a network device in your test lab that was supposed to be a drop-in replacement for older technology already installed in the office (which is a unique environment that's not repeated anywhere else in your organization), then had the new device fail to work when it was plugged in without having someone tweak the configuration?
And it's often the "low hanging fruit" that causes the problem when it's something out of the ordinary...like that someone had to force the port from autonegotiate to 100mbit because there's a flaky connection somewhere between the device and the core network so the autonegotiated 1000mbit connection wouldn't stay up, and building management refuses to replace the network cable.
In this case, they discovered metal filings when they unbolted the old unit, and though they sprayed them out with compressed nitrogen, there was apparently significant enough thread damage that the new bolt wouldn't go in.
A test lab tries to approximate reality, but it's hard to do a complete simulation of a component exposed to the vacuum of space with repeated and severe heat/cool cycles as it's exposed to and shaded from the sun.
I don't doubt that they tested everything right down to the exact same bolts (probably machined by the same vendor, and possibly even made from the same ingot of raw metal), but no test lab is a perfect representation of the real-world. Most spacewalk maintenance is rehearsed dozens or hundreds of times on earth before attempted in space.
A bolt and nut system is very simple but especially when manufactured to fine tolerances it can seize due to a small piece of debris or a slight ding to the threads.
In space WD-40 is not really an option.
"The likes of Facebook and WhatsApp are free to those whose privacy is of zero value."
"Do you guys have any ideas?"
The all-too-common customer support query. I wouldn't want to be on that help desk.
What about a bar of soap? Back before WD40 was in everyone's tool chest, a bar of soap was the go-to thing for everything from wooden draw runners to stubborn screws.
Isn't this just "normal" wear and tear?
There's always a designed life for these systems.
After a few years, say hasta la vista baby to $100B.
Take a nut the same size as the offending one and cut across one end with a hacksaw (or whatever you have to hand), then fasten it onto the bolt. After a few times on and off the thread should be somewhat better.
If God forks the Universe every time you roll a die, he'd better have a damned good memory.
Right.
1. Remove bolt.
2. Shine pen camera and light down the hole.
3. Remove foreign object that slipped in there when nobody was looking, or forgot to check first.
It's called the "Law of Small, Easily Lost Items", aka "The Law of Dice".
"Any small, necessary object, when dropped, will travel a distance that is inversely proportionate to the force provided or otherwise available at the moment of dropping, and settle into the most ridiculously inaccessible or otherwise inconvenient location. The level of consternation to be generated in recovery or removal is a multiple of the risk involved in the attempt, times the expense of the most fragile object involved in the recovery, or the physical/mental/emotional pain likely to be generated during a catastrophic failure of said recovery operation."
[End Of Line]
If you're an electrical or computer engineer specializing in networks you should have enough experience to know that a single bent or corroded pin, or slightly non uniformly applied piece of solder can ruin you day.
If you're on site somewhere, especially somewhere remote, it's hard to know just how things will get messed up. What works in a lab is very different than after you've shipped it off some place and tried to get it to behave there.
Before you deploy a network you obviously test it in your own lab under exactly the same humidity, temperature, radiation exposure, altitude and personnel as for on site right? To what tolerance? You also test all of your backup equipment by having samples you store in exactly the way they're going to be stored at a live test sight, so you know what the probability is of something happening to them during storage?
Now we know single bit flip in an ethernet packet is just the sort of low hanging fruit of problems that we have network engineers for right? So I'm guessing you developed your own mathematically perfect CRC that you have published and that we should all use, to solve the 'low hanging fruit' of single bit flip errors? Just like a thread on nut and bolt right - you can take your perfect errorless network hardware, put in an aircraft, fly it to a remote island 12 time zones away you know you, with absolute certainty, that it will work 100% of the time? You should get a PhD and write articles about your techniques, the rest of us could really benefit from that.
Maybe you're not on the software side of things, but more hardware, say telephone twisted pair. Now as you know, the reason we twist pairs of wires is to prevent a signal on one wire from inducing a field on another. So I'm guessing you have some piece of equipment that can verify that all the twisted pair sets of wires you use are optimally twisted? What's it called?
Ok I'll stop being a snide asshole, unless I find out you're one of my former students.
You're right, that yes, good engineering is supposed to predict problems in advance and plan for them. You do as many tests as you can, and hope that you've figured out what problems will arise. Unfortunately, it doesn't always work perfectly, there's always some random error involved, that you have to cope with on the fly. On the ground I would say 'try another bolt', up in space, when you've got a dude in a space suit simple solutions become very expensive, time consuming and very risky. I used to do something very similar to network engineering as an on site guy, and problems that take 5 minutes to solve in the lab can take hours in the field. And think about the problem they're having they removed an old unit, and in doing so a bolt shaved. They don't, apparently, have spare bolts easily accessible for this. Now they have a tool that can apply more force to the bolt, but that could break the bolt, so rather than trying it (and it might work, and everyone is happy, and no news story gets posted on /.) they decide to take some time, think about it, probably test out a few scenarios on the ground, and go from there.
Notice also how they seemed to have some idea what to do when there were shavings from the bolt - they tried to blow away the pieces with nitrogen - someone planned enough to figure carrying a can of nitrogen might be useful, but I suspect that's a tricky problem with gloves on where you can risk puncturing the glove.
Trying to work in space, and to a lesser degree underwater, is very much an exercise in trying to not make things worse - even if you think you have a solution to this problem you're better to not screw it up and wreck hundreds of millions of dollars in equipment or a bolt that probably several hundred if not several thousand dollars to even get there (a single 100g bolt would cost anywhere between 400 dollars and 4000 depending on what launched it there).
Anyone with a beard would have welded that sucker together already!
Maybe if the can apply heat to the nut it will loosen to the point where it turns more easily and take it off. Use a die to clean up an repair the bolt's threads. Send up another nut on the next trip that's tapped out a couple mils oversize, with graphite or maybe buckyball lubricant and a split-ring washer to hold it in place.
What are you going to make it out of? It has to function in a vacuum over a wider temperature range. 5W20 oil will evaporate. The Hasselblads sent to the Moon had, as I recall, all the bearings replaced with PTFE so they could function lubricant free. (There is still at least one left on the Moon, if you want to collect it, but it's out of warranty).
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."
Get the beeswax up there at reasonable cost. SCRAMjet propelled bees?
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."
Such progress! Surely human colonization of the solar system is months, nay weeks away by now! Elon? Richard? Let's go!
its *certainly* under warranty, right? I would assume so. and you guys all kept the papers? (someone has to have them. check your trunks and gloveboxes).
if you return it in time, you can get a swap. I'm pretty sure.
--
"It is now safe to switch off your computer."
> Not a mechanical engineer, no. I'm a network engineer.
So then...No, you're not an engineer.
Yeah, I was just thinking that the Japanese probably screwed it up by forcing it 9 turns.
They're probably not equipped to fix the problem and new tools will have to be sent. If you or I were up there, we'd want a tool set that could disassemble and reassemble and repair every part of the station and a big box of spares for everything. That's not what they have.
...Like we used to say in the shop -- Cross threads are better than no threads!
Seriously, back it out and try again, does wonders sometimes.
Could be a lot of things, and you can't test space technology 100% without, you know, putting it into space.
Fair point!
I'm not a complete idiot... Some parts are missing.
Are you seriously saying that you've never tested a network device in your test lab that was supposed to be a drop-in replacement for older technology already installed in the office (which is a unique environment that's not repeated anywhere else in your organization), then had the new device fail to work when it was plugged in without having someone tweak the configuration?
For mission-critical networks, we have a lab setup which precisely emulate the production network: same ports, same software, same physical connections. The only difference is physical. In those cases, reconfiguration means someone messed up a test.
I'm not a complete idiot... Some parts are missing.
Very true! If I have a difficult time removing or installing a bolt (removal especially), often you can use heating or cooling on the various pieces to make it easier. It's odd using a torch on one piece and ice on the other in an attempt to dislodge something. I can't imagine how the interplay between different materials could impact things while in space given the huge swings in temperature.
The bolt may fit fine but be crooked. Add to that the temperature going from -250F to 250F and it's not as simple as simple minds think.
I hope you learned your lesson here: don't criticize NASA, or be prepared to be modded down.
Not only that, how is the heat transferred to the bolt going to behave without convection to carry it away? How are you going to heat it in the first place? Can you do that in a space suit? Can you do that safely in a space suit? "Space is tricky. Really, really tricky. Honestly, you have no idea how mind-bogglingly tricky it is, I mean, you think it's tricky having to manufacture cadmium free tools to work on titanium coated hypersonic jet aircraft? That's a doddle compared to space..." (with apologies to DNA)
Please consider this account deleted, I just can't be bothered with the spam anymore.
Do those mid-2000 Dells run in space?
Apart from the already mentioned assembly technique of tightening all bolts incrementally, if there were power tools aboard such as a dremel, the astronauts could have made a makeshift tap out of one of the bolts by simply cutting a groove along the side. The tap could have been used to clean the burrs out of the threads.
Presumably you also test your systems in a vacuum and 300C swings in temperature? Conditions in space are very hard to replicate on the ground and all sorts of weird things happen to metal-on-metal contact in vacuum. The problem here could be (a guess/example) something related to 7% extra torque being needed because of a temperature swing which then bends the male threads slightly, exposing an non-oxidised layer which then vacuum welds to the female thread. Could be a lot of things, and you can't test space technology 100% without, you know, putting it into space.
I thought the whole reason why space bolts are expensive is the vacuum and extreme temperature changes thing.
but why use bolts in the design in the first place? I mean, who wants to turn nuts and bolts in current space suits. friggin nobody.
but maybe they're now just going to wait couple of days and temperature cycles and go tap it after that..
world was created 5 seconds before this post as it is.
Did they bring an extra bolt?
if they just cross threaded the beeeatch.
"Erm... Houston, we have a problem. Poindexter just cross threaded the space station."
Flappinbooger isn't my real name
Actually, vacuum and 300C swings in temperature are pretty easy. This kind of testing is done routinely in labs all over the world.
Spit on it.
Bolts are never reused in flight qualified spacecraft whether manned or unmanned because once they are used the threads become slightly deformed and do not hold as securely as the first time they're used. You can be sure this situation was tested many times with flight prototypes using identical bolts and I'm quite sure the particular bolt causing the problem was inspected quite thoroughly, but you are correct in that it would never have actually been used previously even for testing.
9/11 Eyewitnesses to Explosive WTC Demolition 1 of 2
How much you want to bet it's yet another imperial vs. metric error? This has been a recurring problem with NASA due to the fact that many of it's suppliers are based in the US, and the US, inexplicably, insists on being the only country on the planet stuck in the pre-metric dark ages. An ounce of prevention is worth 1.7086 kg of cure.
Have You Tried Turning It Off And On Again ... or hit it.
I wonder how long the Slashdot editors spent thinking of a word for "bolt" that starts with S.
Isnt getting all words of a headline starting with the same letter something like a journalgasm for journalists?
you're obviously not an engineer. the big things are made up out of tiny things. its always* a tiny things that gets you
Not a mechanical engineer, no. I'm a network engineer. And when I build a network, I make sure to catch the "low hanging fruit" when I test things.
And when it comes to testing bolts, even with my non-mechanical engineering background, I can see that this is low hanging fruit. Will this bolt be able to turn 15 times in this configuration? I'm sure NASA would have been able to test that in their fish tank, and they probably did; with a different bolt...
You think like I do (I'm software dev). I code to try and catch all the scenarios and gracefully recover, but it's impossible in most every non trivial system to do that to completion. Preemption works up to a point, but neither one of us, or even our collective teams, can think of of all scenarios beforehand. We, as you say, generally do get the "low hanging fruit" and a few harder problems, but there'll be unexpected events. There always are.
I've read that the thing that made Apollo so successful, from an engineering standpoint, was not just the planning for contingencies, but the preparation to provide a robust response to the issues that actually crop up, both foreseen and mitigated, and totally unforeseen. To reuse the old joke, not only make the pen work through all zero gee failure modes, but also be ready to use a pencil.
It'll be interesting to see what the response to this issue is going forward.
get a rat-tail file after it. you know the old fashioned triangle file, or a thread cleaner. Always works on earth.
Imperial nut.
Maybe that's why you heard about a bolt problem for the first time today. Working bolts don't make it into the news as easy.
Maybe to attach and remove things easily, but reliable? What other technique would you suggest? The stuff some other commenter mentioned: Duct tape? Or Velcro? Zippers? Gravitational or mental forces? Faith?
Screw did immediately come to mind. However, although my sense of literary license allows screw and bolt to be synonymous,
it seemed necessary to avoid the purist's obvious beat-down scream that Bolt!==Screw. Then, there was the idea
Space Walker was two words -- George Lucas probably the one responsible for changing it to the debatable one word due to Skywalker.
About then is when it occurred to me that I'm taking this way too seriously.
(Not sure if it's okay to admit to not knowing the meaning of "S-walker". Is it? If it isn't, never mind.)
.
Yesterday's Weirdness is Tomorrow's Reason Why
Are you seriously saying that you've never tested a network device in your test lab that was supposed to be a drop-in replacement for older technology already installed in the office (which is a unique environment that's not repeated anywhere else in your organization), then had the new device fail to work when it was plugged in without having someone tweak the configuration?
For mission-critical networks, we have a lab setup which precisely emulate the production network: same ports, same software, same physical connections. The only difference is physical. In those cases, reconfiguration means someone messed up a test.
Well that's kind of the problem -- the physical environment. Equipment that works fine in test may not work in the real environment. For example, when you replace that old access switch that has a 100mbit trunk back to the core, you mean find out that the new switch that works great at 1gbit in your test lab works sporadically in the field because the building wiring is substandard can't support gig, if you pin the connection to 100mbit it works fine. (or replace the wiring if that's an option)
Or, in the case of the ISS, it means that the the test environment couldn't replicate the conditions in space (which, literally exist nowhere else on earth), which led to a damaged bolt when removing the part, and then the current difficulties with installing the new one.
There's probably a billion people out there who've been been screwed by a bolt that didn't have lubricant applied.
I'd do a study on the various methods to average the knowledge from all that to make a decision but no time for that in a proper way I guess.
Pen trading spray is the thing you need. I I assume that has been tried.
Sorry I can't help but chuckle when I see this old chestnut in this setting...
In lieu of the right spray we've used wd40 but not sure that would penetrate without gravity.
The next one would be applying shock or vibration. You could do this within safe limits. Another one could be heating the nut while drawing heat away on the bolt. Perhaps there's some kind of conical reflector for that?
A blog I run for the wealth
"lug nut fixed it" - Name that movie.
If you guys have any thoughts or ideas or brilliant schemes on what we can do, let us know.
Slashdot shop rates
Have gnu, will travel.
"I would expect that in 2012, NASA engineers would be capable of producing bolts that fit."
Yes, they have an app for that.
"They should be getting 15 turns, but are only getting 9."
Occam's razor says somebody used an Imperial bolt instead of a metric one.
"In space WD-40 is not really an option."
Why not? Do you have some special insights?
After all, it was developed for use in rockets.
From WP:
"WD-40 is the trademark name of a penetrating oil and water-displacing spray. It was developed in 1953 by Norm Larsen, founder of the Rocket Chemical Company, in San Diego, California. WD-40, from the abbreviation "Water Displacement, 40th formula,"[1] was originally designed to repel water and prevent corrosion,[2] and later was found to have numerous household uses.
Larsen was attempting to create a formula to prevent corrosion in nuclear missiles, by displacing the standing water that causes it. He claims he arrived at a successful formula on his 40th attempt.[2] WD-40 is primarily composed of various hydrocarbons.
WD-40 was first used by Convair to protect the outer skin of the Atlas missile from rust and corrosion.[2][3] The product first became commercially available on store shelves in San Diego in 1958.[2]"
best bet would be an electric heater manufactured on site out of wire.
Hold the bolt steady, and rotate the space station!
It may have fit fine before 9 turns crossthreaded. Now it's probably space junk.
If the device does not have any moving parts then washers/spacer should be fine. If there were moving parts the torque could snap/bend the fastner so then washers/a spacer would be a bad idea.
Bolts and nuts are relatively cheap, easy to manufacture and very reliable usually.
Given the temperature swings, 0G etc. it doesn't leave much room for other kind of joints. Maybe stainless zip ties could work to some degree.
Pulsed Media Seedboxes
I thought along the same lines; perhaps there is a need to resort to a different style of fastener. They have a space station which should serve as a platform for new technology and once they find that duct tape won't hold forever (does it work at all in space?) I would think that some sort of latch mechanism involving a lever and cam might work. I'm not an engineer, but I was sure scratching my head over why they are continuing to use Earth-based fasteners in a space environment. Of course, flippiing the lever on a cam isn't as sexy as using a multi-thousand dollar ratchet.
OK, so WD-40 is a water-repellent which happens to be a penetrating oil here on earth. There are other penetrating oils, such as the graphite-based one from 3-in-One. I have no idea if they work in zero-grav and hard vacuum, but presumably someone in NASA does, and is either using them or has discounted their use. Job #1 is to fix the problem, and I'm sure they'll come up with a way, even if it means duct tape. Job #2 is to prevent this class of problem reocurring, and that's a design problem for the long term. This space stuff was always going to be a learning curve.
Those rockets you mention are not meant to operate in 0G vacuum under huge temperature swings without convection to aid ...
Likely WD-40 turns to gaseous form in vacuum, would be my guess. But who knows.
Pulsed Media Seedboxes
This isn't an English/SI issue is it? Please tell me we have an all metric ISS.
Must be of lesser quality metal then ...
I got bolts which are meant to be reusable for "as many times as they are undamaged to the naked eye". They are very expensive very high tensile strength bolts, studs and nuts meant to hold very high forces in some cases extreme temperature changes, potentially from ~-40C going to +100C in few short minutes while other metals around them are at unevent temperature and different material, therefore different thermal expansion. Any sane person will allow some warming period before actually putting their strength to the test when peak temperatures can become as high as 1200-1300C.
What are they, you ask? .... That's some wicked pressure and heat peaks! ... Experiencing some extreme revolutions (you know, 4stroke engine doing 18k RPM as per ignition, is doing hell of a lot more at crankshaft and connecting rods ...)
High performance engine fasteners, for example:
- Flywheel which is connected directly to crankshaft... If it comes loose, somebody is likely to die
- Cylinder heads. Imagine the pressure when you have 10:1 or higher static compression ratio and you are pushing more than 3 bars of boost pressure, in a gasoline engine or a diesel engine pushing 7-8bars of boost pressure
- Connecting rods and crankshafts
They are always fastened to very precise, and usually very high torque, preferrably using molybdene based lubricant, but even higher torque if using somekind of assembly oil (traditionally some 30W mineral oil...). If try torque rating is 90nM (quite usual), then molybdene torque rating is around 105nM and with oil can be 120-130nM and that's not even a particularly special case, using JUST 8-10mm diameter studs.
I got some studs which costed 18€ each at wholesale prices, and these are mass produced afterall, available to anyone, made from high strength steel and not some unobtainium.
10 of those TINY studs + bolts + washers might be holding down the force generated by a 1liter turbocharged engine revving to 10k RPM and upwards, while producing more than 600hp at the wheels... dyno failed at that point, not enough grip, and that was at quite mild boost because there was not enough cold air to be used for cooling the engine... This particular engine was ran at the salt flats on even higher boost ratio.
or a 13k RPM screamer 1.6liter naturally aspirated engine with EVEN HIGHER peak pressures, charged engines have actually lower peak pressures than naturally aspirated engines. and yes both of the engines is still roughly at the reach of anyone motivated sufficiently and meant for a car. First one had actually displacement reduced significantly.
Do you really think NASA is not using bolts, nuts and studs of AT LEAST this kind of quality?
That being said, they probably should use studs in exterior fastening, exactly because of the reasons mentioned in TFA.
Pulsed Media Seedboxes
"In space WD-40 is not really an option."
Why not? Do you have some special insights? After all, it was developed for use in rockets.
Well, I've never tried it on my own space station so you may dismiss this as not a "special insight." But applying WD-40 in a complete vacuum, to a jammed metal fastener connection that swings in temperature between roughly -250F and +250F, probably exceeds the recommended use instructions on the side of the can.
I bet the americans supplied the wrong bolts. It wobnt be the first time they mistook Metric with Imperial. This is the Mars lander incident all over again.
This is like trying to fix a car over the phone. What size bolts? What are the materials involved? Galling of threads?? Is bolt softer than the piece it's screwed into? Is a photo of the offending parts too much to ask for?? They don't really want our help, do they?
Sorry, but gray text on gray background is making my eyes bleed.
This is one of the problems with robotic missions... these weird, out of the ordinary events. If this had been a robotic mission it would have been Galileo all over again. "We didn't think this would be a problem so we didn't build to solve it. Now we have to live with the workaround."
Robots are fine for simple things but as the complexity of the machines increases it becomes easier to go with the count on the army of humans who would be willing to make the journey.
Of course they are, they merely have higher standards for spacecraft (especially manned spacecraft) than anything you are accustomed to. Even an unmanned spacecraft is far more expensive than any terrestrial engine you've ever worked with. Do you really think I have never worked with NASA spacecraft? Would you like to hear about the $50,000 toggle switch boondoggle on the STS? It is after all, only taxpayer money.
9/11 Eyewitnesses to Explosive WTC Demolition 1 of 2
But it might lead to premature re-entry.
http://www.myconfinedspace.com/2009/07/20/its-never-miller-time-in-space/bloom-county-jpg/
GUYS:
Exec 1: "Hey, I was trawling the Wayback Machine last night, and I found some old site with an article about you."
Exec 2: "No, you didn't."
Exec 1: "Yes, it was about-"
Exec 2: "No, it wasn't."
Exec 1: "Yeah, it was! You looked a lot thinner in the picture, but it was definitely you."
Exec 2: "No, it wasn't, I'm telling you."
Exec 3: "Was that back when you were 'T13 f00n'?"
Exec 1 and Exec 3 giggle.
Exec 2: "You guys are cunts."
CHICKS:
Exec 1: "Are you attending the conference, Mary?"
Exec 2: "I've told you, my name is 'IT Goddess'!"
Exec 1: "No, it isn't. You're Mary."
Exec 2: "I'm not! I'm 'IT Goddess'! How hard is that to remember?"
Exec 1: "But your real name is Mary, though, right?"
Exec 2: "It's not! Look at my driver's license!"
Exec 3: "Oh, hello Mary!"
Exec 2 bursts into tears.
Exec 2: "YOU FUCKERS!"
Read: http://www.nasaspaceflight.com/2012/09/iss-program-recovery-plans-mbsu-1-installation-failure/.
And you will see that this is more than simply a problem of keeping the thing attached. They actually need that bolt to pull the unit down into a precision-engineered housing containing the electrical connectors that make the unit usable. I grew up with a healthy respect for duct-tape, bailing wire, and JB-weld, but this ain't the place for farm-boy engineering!
Put a pipe on the wrench, crank that baby! If you wonder about the hole left, ream out the hole after the bolt is out, tap new threads, use a slightly larger bolt. DONE! What kind of engineers don't already know this?
Now we know single bit flip in an ethernet packet is just the sort of low hanging fruit of problems that we have network engineers for right? So I'm guessing you developed your own mathematically perfect CRC that you have published and that we should all use, to solve the 'low hanging fruit' of single bit flip errors?
Actually, CRC algorithms can be designed to handle all single-bit errors, and even larger errors perfectly. For example, it's possible to design a checksum to detect all contiguous "runs" of erroneous bits up to a certain length.
Similarly, it's not at all unusual for mechanical designs to cater for the loss of a single fastener, or even several in a row.
Designing a critical power supply module so that it cannot be installed without every single bolt in place sounds like asking for trouble. Maybe it was done in the interests of saving weight, but still...
This stubborn bolt incident may turn out to be a blessing in disguise
So far we human have been using many of the same things that we use on Earth and applying them on exotic locations, such as space
Inside the gravity well, whenever we meet with a stubborn bolt problem, we have many means to solve it - either apply lubrication to the bolt to make it easier to manage, apply brute force and get it in no matter what, or we throw away that stubborn bolt and replace it with another bolt
But on space, such options are not available, and/or not applicable
Maybe this whole thing is a blessing in disguise
Maybe, out of this experience, someone will come out with another method to affix two things tightly together, without having to rely on bolts and nuts
Muchas Gracias, Señor Edward Snowden !
but maybe they're now just going to wait couple of days and temperature cycles and go tap it after that..
Worked on my honeymoon!
Why, without your clothes, you're naked, Miss Dudley!
Actually, CRC algorithms can be designed to handle all single-bit errors, and even larger errors perfectly.
I specifically used the term perfectly because all CRC have a probability of failing due to multiple bit flips that produce the same CRC. The better the CRC the lower the probability. CRC's sort of by definition will find a single bit flip.
Similarly, it's not at all unusual for mechanical designs to cater for the loss of a single fastener, or even several in a row.
Sure, assuming something could go wrong is part of any design. As you say, with the space station it might be a weight issue, it might also be a matter of how long it takes to do the install, or how hard that would be, or the likelyhood that if you have 4 bolts one of them will be bad and mess up everything else.
They're also just sitting on this problem for like a week because it's not all that serious in the short term, and it's possible it will run with 9 turns rather than 15 and all of that. Why take risks when you don't have to after all.
Geometric dimentsioning and tolerancing to the rescue. What do the Engineers that Designed this say?
Can any other measurements corroborate the seated-with-9-turns status?
If you take this and another bold out, and reinstall this one, will it seat, leaving the new #4 bolt a few turns proud?
Somebody forgot to check the thread pitch!
Story Musgrave. He was in charge of fixing the Hubble, and is a complete bad-ass. He has a "good-old farm boy" attitude, that is exactly what you want for fixing machinery in remote locations.
And some duct tape can go a long way! As seen on Mythbusters...
Push for the title to be protected by law, or stfu.
or maybe using an Imperial bolt in a metric hole?
It is an International space-station after all.
Nice one. And so true it hurts.
and heating it? Works on rusted bolts...
It sounds to be like the thread pitch is wrong to me.
New bolt and a few new ones with a slightly different thread and something to take a cast of the thread that's needed to be mated against if the new ones don't work, so a correct one can be made.
"In space WD-40 is not really an option."
Why not? Do you have some special insights? [...]WD-40 is primarily composed of various hydrocarbons
Hydrocarbons have a vapor pressure, which means they will evaporate in space. You have to use something like molybdenum sulfide. About a decade ago, I saw a proposal to us metal-sulfide fullerenes to make the worlds smallest ball bearing, but I haven't heard about it since, so it probalby didn't work out.
if the shavings are still stuck in the threading, perhaps inserting a small magnet would be able to clean them out?
No, Occam's razor says that from available theories you should choose the one that makes the least assumptions. Assuming that NASA made the same mistake twice is not impossible, but it's still an assumption, and given that they are much more careful to double check that facet these days, it's not a likely one. It's much more likely to be either material degradation, which is a basic fact of life and not so predictable under the conditions of space, or operator error, which is also a fact of life. Sometimes a bolt goes in at just a hair of the wrong angle, bites the threads, and for every turn you make you compound the damage. Since these things are things that conform very much to the actual article, they are the lesser assumptions.
Or to put it differently: I don't think that term means quite what you think it does.
I think the lesson is don't be a know-it-all prick.
-> duct tape?
Dremel + zero-G = sharp metal filings floating EVERYWHERE!!!
Personally, I like anaerobic adhesives. I spent time researching them when I was an R&D engineer, and they have never let me down when properly applied. But they are not the best for things that have to be routinely replaced.
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."
Send a tap up there with the next supply run (or better yet a set of them) to clean out the threads. And then use some blue locktite. It's a big machine. They should have a full set of tools to fix it. It shouldn't be all components. One of the things the space station should be for is to learn how to do these kinds of things (mechanical maintenance). Installing some monolithic component sent from earth really isn't the same thing as doing mechanical work. In the future people will need to be able to really fix shit say halfway between here and Mars, or Titan, or Europa. No one is going to be able to just send up a new power module and have guys on earth adequately handle your power for you while you're orbiting Jupiter. Send them some real tools and tell them to fix it. Start learning how so they teach the lucky ones who will follow.
-- I ignore anonymous replies to my comments and postings.
Stick a big enough lever on there, and you can move the world!
[WARNING: Do not try on actual Earth]
swap it with other bolt, removed from other power-switching unit. sometime it helps.
Cut a vertical slot in the bolt so the metallic particles have a place to get out of the way instead of jamming the threads.
Unscrew 1mm. Insert C-shaped washer. Screw in 1mm.
Interesting you mention cylinder heads, considering that many of them specifically use single-use-only bolts where the threads specifically deform to ensure a more permanent grip.
Don't believe me? All Ford vehicles using a modular engine (and that is a LOT of Ford vehicles) have this design. I'm certain others do too. The shop manual specifically explains they must be replaced, and no, it doesn't suggest that for everything to make Ford money. And cheap people who DO reuse them enjoy coolant leaks.
Having spoken with an automotive engineer, bolts with purposely deformed threads are getting more and more popular as they ensure a better fit--they're called torque to yield bolts. They do cost more, but that's progress!
Chances are NASA would use bolts like that because the last thing they need are bolts that fall out or don't tighten to spec. They don't want old style bolts like you're using where you'll need to get them perfectly torqued with a torque wrench to ensure they don't fall out and don't strip. Can you imagine how much of a pain in the arse a torque wrench would be to use in space?
And *this* is why I fix my own car.
even apple know that power supplies are better attached via magnets.
I run: Windows, OS X, Linux, FreeBSD. Just because you have a hammer, doesn't mean everything is a nail.
Why not cut the head off of the bolt and then use a nut to secure the box? Surely if the other end of the bolt is stuck this should be secure enough.
A bunch of magnets taken from dead hard drives. I'm serious. I have a cantilevered shelf attached using a couple dozen of those. You take it off the wall by having two adults hang off the end (about 1300N total). Dead simple. If you didn't have gravity to help you out, you could add a leverage point and use a breaker bar to pull it off.
A successful API design takes a mixture of software design and pedagogy.
So many words yet so irrelevant... We're talking about a bolt that's holding down a power supply, not a freaking engine head. It doesn't have to hold it down with a particular force in order to guarantee performance of the head gasket, for crying out loud. It's a bolt that ensures that the power supply stays in more-or-less in place, with all the connectors fastened and not moving enough to cause wear and eventual contact failure. The only thing this bolt needs to do is stay put and not unscrew itself in presence of thermal cycles. It sees minimal dynamic loads otherwise, the space station is not a fighter jet. Geez.
A successful API design takes a mixture of software design and pedagogy.
Once you develop to IEC 61508, UL 1998 or the like, I'd call it proper software engineering :)
A successful API design takes a mixture of software design and pedagogy.
Call Ed China
Sharp is not that big of a deal. I'd think that their optical properties are a much bigger issue. Presumably they have star trackers, windows and other optical paraphrenalia out there on the ISS. Wouldn't do much good flying in a cloud of reflective dust now, would it...
A successful API design takes a mixture of software design and pedagogy.
I love these holier-than-thou nose-in-the-air dick-waving contests that exist with the term 'engineer'.
By "love" I mean remark on how petty it is.
Hey! Has anybody heard of bailing wire and masking tape! Holds down lots of things!
We'd also want ponies, but given the economies in getting mass into orbit, we would have neither ponies nor a complete Craftsman rolling toolbox.
> Perhaps it would be better if the summary included something like "a unit test failed", then the CS people would understand.
WHAAAAT, NASA is running unit tests in their production environment? I knew those guys were incompetent!
About a 3 ft long cheater bar.
I hope you learned your lesson here: don't criticize NASA, or be prepared to be modded down.
Yes, apparently. Lessons from last week:
- Criticize NASA: modded down;
- Criticize Apple: modded up;
- Want to keep your karma as "excellent"?: get an another account to criticize NASA.
My comments had nothing to do with bashing NASA. NASA is great. NASA is awesome. If they'd pay any better, I'd be applying for a job. I was just wondering why the F something as simple as a bolt could become such a big issue. And that curiosity has been answered by many. For which I am grateful. Thank you, Slashdot, for these 4 lessons learned.
I'm not a complete idiot... Some parts are missing.
One of the bolts is fine thread. You just forced it into the helicoil insert. Remove the bolt check for debris check the thread size and replace the helicoil and rebolt that puppy.
I got a cousin who drives a train, he's an engineer
Or you could just destabilize the magnetic field and pluck it like a flower bud. Non-enginner folks just dont understand what we talking about here.
If you got some metal washers that fit at your disposal, you could unscrew the bolt, put the washers on it, then start screwing it down. The washers will close the distance from the missing 6 turns. That'll tighten it down adequately until the next mission when you can bring some extra tools out there into space (such as a wire brush perhaps) that you can use to scrape out whatever piece of space dirt is clogging up the threads inside the hole and keeping it from screwing all 16 turns.
How would you "destabilize" the magnetic field of a permanent magnet short of putting a hefty electromagnet next to it, or heating it up past the Curie temperature?
A successful API design takes a mixture of software design and pedagogy.
I have a suggestion not a fix. Suggestion is that from episodes of Star Trek. Replicators, we don't have them yet but gives the ability to create items on board the Enterprise and well any federation ship. If they had those on the ISS they could simply recreate the bolt, based on the article wasn't clear if they were trying to remove the bolt or screw it back in. Sounds like they wanted to screw it in but it wasn't happening. More to the point we don't have replicators we do have 3D printers the closest we really have to replicators. If they had a 3D printer on board they could simply create a new bolt with new threading.
I could see studs being a problem for astronauts accidentally drifting into them and tearing their suits.
What I think might be a more interesting fastener for attaching components (such as solar panels) up in space would be a plug type device (think boat plug) with a toggle that can be opened and closed to fasten and unfasten. A more sophisticated version might have a "fingers" that extend into a ringed groove found within the socket. As the toggle is closed the fingers pull the plug tightly into the socket. When the toggle is opened the tension between the fingers and the groove is released and the fingers pull out of the groove allowing the plug to be removed.
Two of my imaginary friends reproduced once