Foam composition and application on the shuttle external tank

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Anyone have details on the Foam, ie its composition..some data on its manufacturer..anything on how it is applied to the Shuttle External Tank would be great. I have an idea on the foam braking away during lift off, but this is purely based on factors I have been trying to tackle with, that are not stress related, so until I know everything about the Foam and how it is applied to the tank, it won't make any sense.

Any tech links would be greatly recieved, thanks.
 
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Most of the External Tank is insulated with three types of spray-on foam. NCFI 24-124, a polyisocyanurate foam applied with blowing agent HCFC 141b hydrochlorofluorocarbon,is used on most areas of the liquid oxygen and liquid hydrogen tanks. NCFI 24-57, another polyisocyanurate foam applied with blowing agent HCFC 141b hydrochlorofluorocarbon, is used on the lower liquid hydrogen tank dome. BX-250, a polyurethane foam applied with CFC-11 chlorofluorocarbon, was used on domes, ramps, and areas where the foam is applied by hand. The foam types changed on External Tanks built after External Tank 93, which was used on STS-107, but these changes are beyond the scope of this section.
- from http://anon.nasa-global.speedera.net/anon.nasa-global/CAIB/CAIB_lowres_chapter3.pdf

I believe this is from the CAIB report, but I haven't confirmed it.

See also - http://en.wikipedia.org/wiki/External_Tank

and - Modification of Space Shuttle Tiles? - post 11
 
Last edited:
FredGarvin said:
He's good like that ;-)
So are you Fred :wink:

Spin_Network said:
A very generous array of links and data, many thanks.

There is also some useful photos showing how the complexity of the Space Shuttle External Tank at - http://www.nasa.gov/centers/marshal...lery/photos/photogallery/shuttle/shuttle.html

The major problem for the foam is the PAL area and Bipod region. The Bipod area creates significant turbulence - vortex shedding off the cylindrical structures.

It appears that the area on ET-121 (on STS-114, Discovery), which lost the foam, was a patch and blend repair. There is definitely a need for improvement in this area.

In reality, the foam loss is only significant on the shuttle side of the tank or roughly 1/3 of the circumferential surface. A kevlar mesh with about 5-8 cm pitch and located just below the surface of the foam would seem reasonable to ensure a reduction in foam loss - but perhaps easier said than done.