Re: Shuttle indefinitely grounded



"TNSAF" <NotMyAddress@xxxxxxxxxxx> wrote in
pUVFe.58056$%K2.10832@pd7tw1no:">news:pUVFe.58056$%K2.10832@pd7tw1no:


>
> Do they form this foam over the tank or is it made first and attached?
> Sounds to me like they need a reinforcing fiber in the foam to act
> like rebar does in concrete. As we know concrete can crack yet retain
> all its strength.

The foam is sprayed onto the tank surfaces; apparently it doesn't adhere
well to some surfaces. A while back the 'blowing' agent was changed
to something 'non-polluting' which reportedly resulted in more brittle
foam. Fibers might help (glass fibers are used to reinforce concrete too)
as might a slightly rougher surface for the stuff to bond to.

The fix will need to be a simple as possible, or it will add new
complexities and problems.

I think the Delta IV CBC uses the same foam and might make a good
test bed for changes. The Heavy configuration could roughly
approximate the Shuttle stack.

--Damon
.