🚀 go-pugleaf

In an article about the adapted Boeing 747 shuttle-transfer aircraft in
the June '89 issue of Spaceflight News, I read that there are a number
of constraints governing the ferry-flights.  One of these constraints is
that the flights cannot take place when there is danger of rain because
this apparently is bad for the thermal-protection tiles on the orbiter. 

If this is so, what happens to the tiles if the orbiter is sitting on
the launch pad and there's a rainstorm? How does rain affect the tiles?
Or is it because flying through rain at high velocity (up to 250mph in
the case of the STA) would act like a high-pressure hose on the tiles
and damage them? Surely 250mph rain can't be as bad as 17000mph air
which the orbiter meets on re-entry?

-- 
Andy Clews, Computing Service, Univ. of Sussex, Brighton BN1 9QN, ENGLAND
JANET: andy@syma.sussex.ac.uk   BITNET: andy%syma.sussex.ac.uk@uk.ac
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