For all the technology and engineering brainpower being thrown at the
foam problem, it bothers me that NASA is essentially flying four
versions of the tank on succeeding flights: the "old" ET carried on the
fatal Columbia flight (STS-107), the modified one used on last year's
"return to flight" Discovery mission that resulted in more (although
not deadly) foam events (STS-114), the one being used on this flight
(STS-121), and the one slated for the shuttle Atlantis on the next
flight (STS-116), which will have further modifications already decided
on. It's not clear to this non-engineer that the accumulation of data
from flying four designs isn't so complex it could actually conceal a
problem rather than spotlighting it.

Matt Bille
www.mattwriter.com

Pat Flannery wrote:
Scott Hedrick wrote:



Although the idea of putting pinholes in the foam to allow any trapped air
that got liquefied under the foam to vent safely when ascent heating
caused it to go back into a gaseous state without causing the foam to
debond solves one problem, it also leaves a way for water to get into the
foam.



Which you solve by spraying the holes with a sealant.



What they really needed, particularly given the Cape's wet climate, was
a building that could entirely enclose the Shuttle to just an hour or so
before launch, like Vandenberg was going to have for its Shuttle launch
facility.
In that way you could pick a nice sunny day to roll the Shuttle out to
the pad from the VAB, and keep the rain off of it once it had arrived.

Pat