On Wed, 15 Sep 2010 23:54:02 -0400, JF Mezei
wrote:


as of today could the shuttle get a reprieve?

Yes.

What I find interesting is that it wasn't long ago that it was stated
rather categorically that there were 2 tanks left with absolutely no
change of additional flights until the tank manufactiring could be
ramped up again (a couple of years).

Not long ago? STS-134 has been on the books for well over a year, and
that meant one of the "2 tanks left" was pressed into serivice for LON
back then. ET-122 (the Katrina victim) and ET-94 (the elderly LWT)
have been known to be sitting around for a long time now. But both had
problems: ET-122 would need to be repaired, something that makes NASA
nervous in the post-Columbia period, and ET-94 was a guinea pig for
the CAIB and needs a lot of work to be put back into flightworthy
shape, even then it comes with a 7,000 lbs. payload penalty (its a LWT
not a SLWT.)

The parts for other Tanks is a big unknown. How many parts and what
are they? How long will it take to build the parts that don't exist?
How long will it take to certify the new foam (the old foam is now
defunct.) How long will it take to get back all the employees who know
how to build Tanks?

So it was true that there were only 2 tanks left. The parts for others
are decidely a question mark (if you have to build whatever parts
don't exist, then we're still two years minimum from being able to use
them.) One of those Tanks (ET-122) was ordered to be put back into
service over a year ago when Congress ordered STS-134 (with ET-122
becoming the STS-335 LON Tank, although NASA might swap the ETs for
134 and 135 to fly the newest tank last.)

Brian