
A Stuck knob?
Everyone knows all you have to do with a stuck knob is apply lubricant, and it'll slip right out. just make sure its water-based, or it might explode.
Paris, 'cos she knows about lube
NASA is pondering how to remove a rogue knob which has firmly wedged itself between a window and the dashboard of space shuttle Atlantis - an apparently minor affair which could actually result in a six-month delay in the venerable vehicle's STS-129 mission to the International Space Station, or even see the shuttle grounded for …
Read the article that's linked from el reg - looks rather serious. Can't drill for fear of damaging the window further - as it stands, looks like the window has been compromised already!
Blame the messy astronauts who didn't clear all the coke cans/mcdonalds bags from the footwells before landing her!
When faced with the choice of driving her car full tilt through a woodland, or driving along the road but wiping out a "sweet innocent fluffy little rabbit" embedded a treetrunk in her VW polo's engine bay. The deceleration force parted the dash from the windscreen for just long enough for a biro to become sandwiched between the two, I believe it stayed there until the car was scrapped.
Christ alone can imagine the carnage that would ensue if they let her drive the shuttle.
“Knob removal attempts should be performed by exhausting least risk options first. More evaluation is required.
I bet theres every scientist and tech there with there own pet "that'l do it try that" idea, just itching to sneak in and give it a go.
"Use pry bar to deflect dash down: Viewed as the riskiest removal method for all hardware involved." - my idea already thought of, they would have had to restrain me from already having a go, i probably would be trussed up in corner with a armed guard for suggesting it.
They are NASA, some of the finest engineering minds in the world, they've already used dry ice, do you think that they haven't thought of cutting/sawing/drilling it out before that? I can think of two problems off the top of my head:
Friction causing heat and weakening the glass
Slipping next to the window glass and fucking it up.
Or maybe they are all stupid, which as they can get people into space and back (generally) safely seems unlikely.
PS: Knob. Hur, hur, hur.
> Christ alone can imagine the carnage that would ensue if they let her drive the shuttle.
it would probably be perfectly fine. There aren't many rabbits in space and even fewer trees to drive into.
(BTW. I wonder how much _more_ damage she did to the ecosystem - destroyed tabbycats, sorry: habitats, run-over beetles and small furry creatures, just to save one of a million bunnies.)
I know of a C-130 (a fairly special one) where a socket wrench socket fell into a maintenance opening between the inner and outer skins of the plane, making sounds like a pachinko game till it came to rest somewhere in the belly of the plane.
Nothing short of un-riveting the front belly of the plane would retrieve it, and even that might not work. They marked the plane as "not flyable" for a week while they thought hard on the problem. Eventually, when it was becoming an issue up the chain of command, they said WTF and just flew it anyway.
I'm guessing that won't happen here for lots of reasons.
Oh, please...
“Knob removal must be performed carefully; exhausting all risk free options first, then attempting more intrusive (higher risk) options, if others fail.”
sounds like a bad Friday night out.
'Inspections of knob have been carried out via borescope'
and that's the result of careless knob removal, a trip to the STD clinic and a thorough inspection with a borescope.
Paris,
If anyone is wondering why they're being so cautious; it's because the Orbiter is incredbly fragile.
The day before Challenger made its final launch in January 1986, NASA had a problem with the orbiter's hatch. When the door closed, a couple of tiny pins should drop into place completing an electrical circuit which confirms the hatch is in place. That day, the pins didn't fall into place. Pressure tests and Mark One eyeball said the hatch was sealed and pressurised, but NASA didn't want to launch without absolute confirmation - they didn't want another Soyuz 11.
So a team was called to the Pad to replace the microswitches, they used a special aluminium tool to hold the hatch in place because they couldn't risk touching the orbiter's protective heatshield. After replacing the microswitches, they tried to remove the tool and found one of the bolts had become jammed. They couldn't use force without damaging the ship, so the only option was to cut the tool away. After a long discussion about potential damage to the orbiter, the risk from stray hydrogen boiling off the ET, they get a drill sent to the pad - the battery is flat from being left in the cold. A replacement was sent and the fix is finally made - but by then winds around the Cape exceeded the threshold for a safe return in the event of a launch failure.
The launch was scrubbed until the next day. The media had a field day that the Shuttle was a dog and made jokes about the staff who'd tried to get it to fly. Meanwhile, that night in Florida was the coldest on record.
So, the failure of one bolt probably lead directly to the explosion that destroyed Challenger.
Which explains why NASA are taking no risks with this one.
The exact opposite observation is also valid.
Namely, the destruction of the Challenger was an indirect result of the scuttle's dependence on complex systems built from unreliable components. This was exacerbated by NASA's inability to perform a relatively simple fix in an efficient and timely manner. Leading to a delay and an unforeseen set of circumstances, where an engineering veto was over-ridden.
So far as the inability to fix a relatively simple problem (caused by a design fault), the situation appears very similar to what you've described, and has not changed at all in the past 20-plus years. Hopefully this time, the engineers will hold sway and their opinions respected.
Did anybody see down at the bottom of the linked document? And I quote:
"L2 members: Documentation - from which the above article has quoted snippets - is available in full in the related L2 sections, now over 4000 gbs in size."
Methinks somebody has a little too much time on their hand with a 25 Mpx camera...how in the *world* does one assemble a 4 TB document?!?
Saw it in half using a diamond-coated wire saw? (Hand-operated, and doesn't suffer from being pinched or nipped like a dremmel saw might. Apart from a spherical diamond I doubt that there's anything one can't cut through this way!
If thermoplastic: melt it? If any polymeric material: attack it with a laser tuned to wreak havoc with molecular bonds in that particular polymer and thereby selectively decompose it?
Drill lots of holes in it until it can be crushed or crumbled? Combine this with freezing with liquid Nitrogen to make it glassy, and high-powered ultrasound if necessary to shatter it?
Vibrate it out (pull hard while it or the panels around it are vibrated)?
I refuse to believe that there is any known material or composite that could not be gotten out of there using at least one of these techniques!
They're NASA. Rejigger a Dremmel, attach a vacuum hose to suck up metal shaving, and cut the damned knob in half. The vac will suck up the metal bits, and you'll know it''s done when the vac sucks up half the knob when you're done.
Well, at least with three orbiters in the mix, if they need to take one out of the mix because of this fuck up (don't they have a spare window pane on the shelf somewhere?), I'm sure the other two can complete the damned job, so we can get around to twiddling our thumbs until the Dragon comes on-line, followed a few years later by Apollo on Steroids.
Yes kids, Steroids are bad, unless you have some localized swelling, or a Space Capsule...
Thy can manage with two Shuttles, but the time it takes to prepare a Shuttle for its next launch means that finishing the ISS will extend well into 2011.
http://www.spaceflightnow.com/shuttle/sts127/090624update/ sounds less pessimistic though. My money's om Atlantis launching in November though.
"BTW. I wonder how much _more_ damage she did to the ecosystem - destroyed tabbycats, sorry: habitats, run-over beetles and small furry creatures, just to save one of a million bunnies.".
More to the point, although both she and her passenger walked away from that one, it was by sheer dumb luck... Fancy knowing that your driver will risk your life to save a rabbit that's stupid enough to be sat in the middle of the road.
I wonder how many furry critters get barbecued or broiled each time the the shuttle launches...
That may work (assuming that the sawing didn't put undue stress on the window) but the consequensces of even a tiny bit of swaf in the cabin, while weightless, could be serious in the extreme.
The two main reasons that pencils aren't used in space is because they chip off little bits of electrically conductive carbon when you write with them. And they are an excellent source of fuel, what with being made of wood. To make this worse, the cabin is a very high oxegen environment.
There are two obvious options. Slap a piece of duct-tape onto the windshield and call it fixed, or use a larger hammer to beat the windshield off, rip the knob out and install new windshield.
6 months is simply outrageous, at worst I could see it taking 1/3rd that to fab a new windshield (if they really don't have another lying about which would be surprising) , then another day to install and a week to test.
Hmmm... if the pressure difference of being in space allowed the knob to get where it could be wedged, I wonder why they couldn't just pressurize the whole interior of the shuttle to 29.4 psia (or 14.7 plus whatever the exact ambient air pressure is that day). 29.4 psia would be 14.7 psig, if my physics knowledge is holding.
This would be similar to what Mythbusters did to a retired jet aircraft body in one episode.
That should result in a pressure differential between the interior and exterior of the orbiter that is the same as that which occurred when the knob became lodged in place. I suppose they could be concerned that the window (if damaged) could dislodge violently, causing more damage to the orbiter. That scenario should be familiar to anyone who has ever worked on old cars.... well, if it breaks when I take it off, I really don't care because I can't use it like this anyway!
PH, because that's the closest thing to an anti-boffin icon on the list ( IANARS = I am not a rocket scientist!).
They can't overpressure the shuttle to 29.4 psia. There are things in there that won't take that much pressure, even though it's only 14.7psid relative to the atmosphere outside the shuttle. Little things, like cabin pressure sensors, pressurization control valves, and so forth. If you take the shuttle up to 14.7psid where it's sitting, you're gonna be replacing a bunch of other stuff. As it stands, they're only allowed to go to 3psid.
... make a tool to remove it. Looking at the diagrams in the linked article, it should be possible to make a custom tool that would bend the petals of the knob without exerting any more stress on the window and retrieve it. It looks like it's made of brass, so it's soft as shit anyway.
If they send me the exact dimensions, I can knock something up for them by Friday, during which time, they could be building a test rig/mock up to make sure the tool works perfectly.
6 months my arse.
They can't cut it out because any sawing/cutting/grinding action will impart high frequency vibrations directly into the window, causing more damage. It would be no different than taking a vibro-etch pen to the window pane.
It is a huge ordeal because this is the INNER pressure pane, not the outer window that is routinely replaced after missions due to debris impacts. This component is not designed to be replaced at the Cape. The only facility with the tools has been shut down over 6 years. To even access the pane to replace it requires extensive disassembly, hence the long timeframe.
Also, the manufacturer of the window has been out of business for about 20 years, so a new vendor would have to be qualified, and the window also requalified. The spare pane was used to build Endeavour.