"Chris Bennetts" wrote in message
...

"Bruce Sterling Woodcock" wrote in message
om...

"MasterShrink" wrote in message
...
And here we are terrified of flying one more non-station mission...

Because we were wrong about non-station missions.

It's like flying a plane with a bomb on board that goes off
1 in every 50 flights when you land. But if you rendezvous
with a special plane in the air, the bomb can be defused.
After 100 flights, we discover this, so we decide from
now on we'll fly only when we can rendezvous with that
plane.

As usual, it's more complex than that.

As usual, that's true of all analogies. Your argument is dead
out of the gate. Of course it's not EXACTLY that... I said it
is LIKE that, to explain it to someone who didn't quite seem
to get it.

A space station mission still has to
survive launch and on-orbit operations - both of those carry substantial
risk, together they are in the same ballpark of risk as reentry. Flying to
the ISS isn't going to eliminate those risks. And still, no inspection
technique available at the ISS is going to be completely reliable at
detecting potential TPS-related risks for reentry.

That's a different bomb completely. I'm only talking about
the one we know about, and the one we know how to fix,
at least for ISS flights.

With the changes to the ET foam, there is a much smaller risk of there
being
any damage to the TPS during launch. That particular "1 in 50 bomb" has
been
largely eliminated. (BTW, where'd you get 1 in 50 from? There was 1 total
loss and several cases of more minor damage from 112 reentry attempts.)

You have no empirical data that shows the risk of TPS damage
is smaller during launch now. None. Zero, zip, nada, zilch.

Secondly, 1 in 50 is LIKE. Get it? It's not the exact figure. It
doesn't matter what the exact figure is for the purpose of the
analogy. Get it?

By focussing too narrowly on one particular loss scenario, you risk losing
sight of many other risks. The causes of the loss of STS-107 are being
addressed. We need to ensure that there are no other problems ready to
bite
once we've fixed this set.

I'm not losing sight of them at all. There are many other
bombs on the plane that might go off. That doesn't mean
then that you shouldn't rendezvous with the ISS to get rid
of one, since there might be others.

And you're complaining, "Hey, you flew most of those
flights without that other plane, why are you afraid
now? The bomb probably won't go off!"

We have removed that particular bomb (we think...). Unfortunately, there
may
be other bombs on board that we don't know about, and that we can't fix
with
that other plane.

Which is no justification for not using the other plane
to remove said bomb. Which is counter to the
previous poster's point.

Bruce