"Peter Kemp" wrote in message
...
On Mon, 15 Mar 2004 14:55:19 -0600, "John Carrier"
wrote:

"If everything goes perfectly on a mission, I would say it's comparable
risk," says Grunsfeld. "But we've seen from Columbia that things don't
always go perfectly. And it's that fundamental difference that on a
Hubble
flight if something goes wrong you run out of options very quickly. And
on
these space station flights we have lots of options."

What I don't understand is - even if the Columbia mission had been to
the ISS it may have all still ended in tragedy.

That is true. But future shuttle flights won't be conducted in the same
"come home as you are" fashion". A mission to the ISS that results in the
detection of damage that prohibits a timely reentry and landing means the
crew becomes extended guests on the ISS; detection of the same damage during
a Hubble repair/service mission does not leave them that option and results
in a rather short timeline within which to launch and complete some sort of
rescue effort.

It only takes a small
leading edge crack to expand in the way we saw, so unless they're
planning doing *very* thorough orbital "walk arounds" of the orbiter
to inspect fro cracks, you're still likely to come back in pieces.
After all the Columbia didn't know their wing was damaged when they
attempted reentry.

Because they did no investigation at all? Agreed that in-flight inspection,
be it by space walk, remote viewing, or a camera mounted on the end of the
shuttle arm, or the likely combination of all three, will not be foolproof,
but you can bet that they pay particular attention to leading edge surfaces.


Oh, and my vote would be to keep Hubble going, but it isn't my bum on
the line, so I won't second guess NASA.

I think it is a shame that it may be allowed to die--but like you I have
pretty good confidence in the professionals' assessment.

Brooks


---
Peter Kemp

Life is short - drink faster