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Stuck Knob Causes Serious Window Damage To Atlantis
FTL writes "While in orbit a metal knob floated between a window and the dashboard of Atlantis. Once back on Earth, the shuttle contracted, wedging the knob firmly in place and damaging the window. Initial attempts to free the knob have failed and engineers may need six months to disassemble that section of the orbiter. Given that the shuttle program will probably end next year anyway, such a delay might mean scrapping Atlantis early rather than repairing it. Efforts to remove the knob using less invasive techniques continue."
why not just put it in a vacuum chamber, warm it up, and slide it on out?
What, you mean like they discussed in the article? They even came up with a better idea: instead of heating up the whole vessel, just freeze the knob with dry ice!
The options relating to the application of dry ice to shrink the knob have already been attempted, and failed. However, the same method, along with a pressurization of the Crew Module, may be enough to free the knob from its lodged position.
The only problem is the amount of pressurization that can be conducted in the OPF is far less than the pressure that played a part in allowing the knob to become embedded in the first place.
Pressurize crew module and dry ice on knob to TBD (To Be Determined) pressure. Pro's: Could allow for uniform structural deflection to increase gap between pressure pane and dashboard; enough to free up the knob non-destructively. Less potential for inducing further damage to the pane.
**UPDATE: The above option was selected on Thursday as the opening process for an attempt to remove the knob. The cabin will be pressurized to 3 psid, before an engineer will apply dry ice to the knob. This option is not deemed to be a likely solution, but more so the opening option that avoids additional damage to the window.**
Although it's lengthy, you should try reading the article next time. The guys at NASA are pretty clever.
My work here is dung.
Or is that only an outer protective layer? I know I've seen pictures of the pitting that micrometeors and paint flecks have caused on the Shuttles while in orbit, I just assumed they were made to be easily replaced.
The article isn't wholly clear, but implies that there are three layers of glass, only the outer one gets replaced. The inner ones have never been replaced on any shuttle. The innermost one is the most important for retaining the internal pressure, and is the one that has sustained damage.
And to be clear, if you read the article, it's obvious that the engineers working on this are SERIOUS and have thought of just about anything that slashdot readers have come up with. Drill/cut? Too high risk because of (a) vibrations transmitted to the window and microgrinding of the knob against the window and (b) metallic dust it will generate. Pressurize orbiter? Yep. For some reason, they think they can only get it to +3 PSI. Might help. Apply cold to the knob to shrink it? Yep. They tried dry ice. Didn't work. (My guess is that they'll try liquid nitrogen, too at some point.) They're planning on trying dry ice and pressurization at the same time. Apply downward pressure to the dash with a crobar? Probably very risky because of unknown damage it might cause to dash.
Once the knob is out, they'll make visual inspection of the remaining surface, including taking microscopic moldings to assess the damage. The pane is tempered, so scratches are a big problem, as they can lead to spontaneous, catastrophic failure.
Put my fist through my alarm clock with its ding-dong death inside my ear. - The Blackjacks.
Nope sorry p51d007
Fisher developed the pen at their own expense NASA only had to buy the pens, at the same price the general public could I might add.
You know, just a little research would keep you from looking quite so stupid.
As a personal note you might try not being an ass, just for fun.
re: http://en.wikipedia.org/wiki/Space_Pen
NASA never approached Paul Fisher to develop a pen, nor did Fisher receive any government funding for the pen's development. Fisher invented it independently, and then asked NASA to try it. After the introduction of the AG7 Space Pen, both the American and Soviet (later Russian) space agencies adopted it. Previously both the Russian and American astronauts used grease pencils and plastic slates