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Crack Found in Shuttle Tank
hpulley writes "The shuttle's new fuel tank, supposedly redesigned to be safer, has a crack in it. Pictures were sent to the manufacturer who decided that it is too small to be worrisome. Hmm, what caused the Columbia disaster, pieces of foam?
Meanwhile, there will be a second shuttle on standby, just in case the first one has problems after being hit by foam, etc. If the first shuttle has a design flaw, what's to say the second one isn't afflicted by the same problem? Won't there be a good chance of them stranding the rescue crew in addition to the original crew? If an aircraft crashes and the redesign to fix it crashes, would you send another of the same type to rescue it? Of course not! The ISS is going to be a smelly, scary place with the regular complement and two shuttle crews onboard and no way home but a Russian Soyuz capsule that isn't slated to launch again until September and has seats for just three..."
If the poster read the suggested articles he would know the crack is in the tank's insulation and not the tank.
If it makes you feel better the shuttles do not use the same computer they did in 81.
They have been updated a lot since they first flew.
The Air Force flys Bombers designed in the 40s and built in the 50s. Fighters that where designed in the 60s and built in the 70s. Even the Boeing 747 was first built in the 60s as was the 737. I agree that the shuttle does need to be replaced but it is not the same shuttle that flew in the early 80s
See my blog http://ilovecookes.blogspot.com/ for light hearted technical information.
According to a couple of people I know who are pilots, the issue with any aircraft isn't physical age, but hours in the air. This is why you can still safely buy and fly a Piper Cub, or, if you're SAC, a somewhat updated B-52, first built back in the '50s.
Those shuttles are probably finally making it to broken in, from an airframe standpoint. (even if they are approaching the day for that one, last, flight to the Air and Space Museum)
the more accurate the calculations became, the more the concepts tended to vanish into thin air. R. S. Mulliken
There is a whole branch of structural engineering called damage tolerance which deals with cracks. The certification process for new airplanes deals with it extensively. For example, we must assume that any airplane can have a .050" crack at any location. Such a crack is assumed to grow, and it might get quite long before it must be found. I'm talking inches in length, sometimes.
Equine Mammals Are Considerably Smaller
I think the submitter needs to study the Columbia report and understand the Aerospace industry a lot more before trying to (and apparently succeeding at) alarming the /. crowd (which, quite frankly, isn't that hard to do).
First, while it was "pieces of foam" that caused the problem, it was decided that it was most likely a single suitcase-sized piece of foam hitting the leading-edge carbon/carbon that led to the eventual destruction of Columbia. The SOFI (spray-on foam insulation) process has been improved to reduce the number & size of voids in the SOFI. The maximum size of foam expected to fall off now is on the order of 1% of the size of the piece that doomed Columbia. Further, the bipod ramp foam has been eliminated in the redesign. Further, they've developed new techniques to inspect the SOFI so they can detect any anomalies. If they found something, which apparently they have, engineers can assess it and determine its severity. I'm not familiar with the specific issue, but depending on its sign & location, it was apparently deemed to not be a problem. Essentially, NASA is probably inspecting better now, so they are seeing more lumps. It doesn't mean that this isn't the best external tank ever built (it doesn't mean it is, either).
And in general, the whole SOFI system has extremely high visibility at NASA (I don't work there) and beyond (I do work there), and if any engineer thought it could be a safety issue, the launch would be delayed.
Not to mention, the tank wasn't "supposedly" redesigned; it was redesigned. Unless the submitter is suggesting that there was a massive conspiracy to deceive the public into pretending the shuttle tank was redesigned when it wasn't (but apparently not large enough to squelch any whistle-blowers), he should refrain from making those sorts of allegations.
The rest of his comment barely qualifies as idle speculation; the rescue crew is a last-resort, and NASA is not anticipating any problems. The idea of preparing a "rescue" craft was in direct response to Columbia when it was asked what NASA could do if they knew shuttle was doomed. If they detect a problem, NASA will assess and decide to either a) land at Kennedy/ Edwards as planned if there's nominal risk (I'd rate that at 95%), b) land in White Sands with a full crew if there's low to (I'm guessing) medium risk (let's call that 4.9%); c) launch a rescue mission and either ditch shuttle if they're sure it's doomed, or land at White Sands with a minimal crew if the think it might be doomed (I'd say 0.1%).
No, I'm not a rocket scientist. I'm a rocket engineer. And I find it sad that Slashdot chose to post this story when I bet there were other, fact-based submissions written by people more knowledgeable about the subject at hand.