Shuttle Foam Crack Puts Launch in Doubt

PhotonBoy

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http://www.washingtonpost.com/wp-dyn/content/article/2006/07/03/AR2006070300238.html

"Monday, July 3, 2006; 10:34 AM

CAPE CANAVERAL, Fla. -- Inspectors found a 5-inch-long crack in the foam insulation covering the shuttle Discovery's external fuel tank, and NASA managers were deciding Monday whether to call off the scheduled Fourth of July launch.

The crack was spotted during an overnight inspection. NASA had scrubbed launch plans Saturday and Sunday because of poor weather and had removed fuel from the tank.

The inspectors found the crack, which was an eighth of an inch deep, in the foam on a bracket near the top of the external fuel tank...."

This is not too good if you ask me. When (or if) they reload the fuel tank with super-cold fuel, additional mechanical stress due to thermal shrinking will likely worsen the crack. Sheesh!!
 

TinderBox (UK)

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you would still have to beat people of with a stick to volunteer to fly on a misson risk or not.

If anybody drops out, i`m in.

how about a group buy, when they retire the shuttles.:lolsign:

regards.
 

scott.cr

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Any of you guys listen to "Coast to Coast AM" on the radio? Last night's guest host said something to the effect of "They expect a FOAM COVERED exterior fuel tank to survive 'Qmax' and the shockwave through the sound barrier, not to mention all the vibration and stress of a launch into orbit?"
 

Manzerick

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amazing that we had so many uneventful launches and now that some foam fell and caused a mess it seems every shuttle has damage to the foam...


DO you folks think this may have always been an issue?
 

Flying Turtle

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I'm thinking they'll spray the crack with some miracle repair stuff and be ready to fly tomorrow.

Geoff
 

PhotonBoy

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Apparently the foam has always shed during launches and caused minor tile damage, but no one thought much of it until 2003 when the second shuttle was lost due to a foam hit on one wing. Although weighing less than 2 pounds, it was traveling at ~200 mph when it hit the wing's leading edge.

They might spray some miracle stuff/glue on the crack, but it's anyone's guess what happens when the tank shrinks with its cryogenic load of fuel.
 

tvodrd

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My albeit-limited understanding is that NASA/Contractors were forced by legislation to develop less-effective/environmentally/politically-correct insulation for the liquidified gas(s) expendable tank. Legislative edicts to material scientists killed some people. Oh well. :shrug:

Larry
 

PhotonBoy

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http://en.wikipedia.org/wiki/Space_Shuttle_Columbia_disaster

From the above article on Wikipedia regarding the Columbia disaster:

"...The composition of the foam insulation had been changed in 1997 to exclude the use of freon, a chemical that causes ozone depletion; while NASA was exempted from legislation phasing out CFCs, the agency chose to change the foam nonetheless. This led to many statements linking the foam strike to environmental pressures. STS-107 used an older "lightweight tank" where the foam was sprayed on to the larger cylindrical surfaces using the newer no freon foam. However the bipods were manufactured from BX-250 foam which was excluded from the EPA regulations and did use the original freon formula. The composition change did not contribute to the accident...."

I agree that the best possible foam should be used -- the long-term environmental impact would have to be minimal, I'd think.
 
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