On the lasting importance of the SpaceX accomplishment.

In article 32fbdc15-236e-4bbe-a95a-
, says...

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The airframes are likewise the only part of ISS modules that can't be
changed. Pretty much everything else can be changed out. It was
designed that way deliberately, Bob.

Brian

Dockings of visiting spacecraft, thermal cycles during each orbit of
Earth, reboost maneuvers and crew exercise can affect the space
station's structural health.

So now you're an expert in structural fatigue? This could be an issue,
but considering the loads experienced by the modules during launch, I'd
think it would take quite a long time for such small loads to cause the
sort of fatigue you're talking about. Please remember that ISS is in
orbit and is experiencing microgravity conditions. This is compared to
the 3 or so g's (plus a lot of vibrations) experienced by those same
modules during launch.

Without the ability to inspect the shell
of the craft, like airplane engineers would do on Earth, NASA must use
computer models to predict how cracks and deformities propagate in
space.

You're speculating here. You have not done the analysis. Cite?

So theres no way to directly inspect the modules, a not anticipated
issue may appear, similiar to the square window issues in the first
commercial airliner. plus space is a very challenging environment

So where are the square holes in the structures on ISS? Besides, space
(specifically microgravity) is *not* a challenging environment for
structures. *Launch* (especially aboard the space shuttle) is a
challenging environment for a structure which otherwise will experience
microgravity conditions.

Jeff
--
" Ares 1 is a prime example of the fact that NASA just can't get it
up anymore... and when they can, it doesn't stay up long. "
- tinker

In article ,
says...

How does this relate to the ISS? You can't pull a full inspection,
taking apart the structure and performing Non-Destructive Testing
on it. We don't have the knowledge base yet to be able to predict
what the long-term effects of the space environment are going to be.
Any predictions now are guesses, surmise, and prejudice.

The materials results from LDEF gave us a pretty good baseline.
Besides, "the space environment" largely consists of microgravity and
either vacuum or sea level air pressure (depending on which side of the
pressure vessel you're talking about).

The airframes are likewise the only part of ISS modules that can't be
changed. Pretty much everything else can be changed out. It was designed
that way deliberately, Bob.

What everybody seems to miss, or ignore, is that the ISS just being there is a
vital part of long endurance spaceflight. If we can't build structures, power systems,
environmental systems, and all the rest that can't be trusted beyond the next
scheduled resupply flight, than anything like a mission beyond the Moon
is right out. Mir was jack-legged together - the crew spent most of their time
(Especially in the later years) working at not dieing. The Russians, and we,
learned a lot, but not enough. ISS's history shows that we still have a lot to learn.

I beg to differ. I think we've learned enough to go beyond LEO for long
missions. Humans have been "doing" long duration spaceflight in LEO
since the 70's. We're coming up on about four decades of long duration
flights. If we're not "ready" to leave LEO by now, then we're gutless
cowards.

Money (the high cost of spaceflight) is what's holding us back, not
technical, engineering, or medical issues. We know how to deal with the
technical, engineering, and medical issues.

Jeff
--
" Ares 1 is a prime example of the fact that NASA just can't get it
up anymore... and when they can, it doesn't stay up long. "
- tinker