Re: Buran Website Finds So Far


"Peter Stickney" <p-stickney@xxxxxxxxxxxx> wrote in message
news:7ccmn2-ck6.ln1@xxxxxxxxxxxxxxx
> As to the "Safety Culture" - I submit that thatreally doesn't come
> into play, here. Up to this point, neither us or the Russians have
> lost spacecraft to simple, obvious problems[1]. Nor have we lost
> spacecraft to the same problem more than once. "Safety Culture"
> protects you against known failures, and works when problems don't
> recur.
>
> [1] "But what about the O-Rings on Challenger, or the Foam Strike on
> Columbia?", I hear you say.
> That there were problems with the O-Rings sealing properly was known.
> But in most cases, the O-Rings _did_ seal properly, and they were
> felt to be understood. If launch conditions had been slightly
> different, or if the burn-through had occurred on the other side of
> the joint, it would have been just another incident to go into the
> stack of data.
> The same goes for Columbia - While there was concern that the foam
> strike (Once it was identified) had damaged to tiles, nobody at the
> time was concerned about the leading edge RCC panels. Those were
> known to be tough - so tough that when the rain erosion and particle
> damage tests were performed early in the program, it was impossible
> to damage them. What hadn't been anticipated was the embrittlement
> that occurred in the panels after having been flown a number of
> times, and the effects of an almost impossible square strike on the
> leading edge. (Due to the curvature of the leading edge profile, the
> chances of a hit not glancing off are extremely small.) That the hit
> occurred in the worst possible locations - where the bow shock
> impinges on the wing during re-entry, was the icing on the frosting
> on the cake.

>From news reports, there is mounting concern that orbital debris
(micrometeorites) can damage the shuttle TPS and cause another Columbia like
disaster. This is potentially another area where there have been hints that
there could be a problem, yet we continue to fly anyway.

Considering how few flights the shuttle and Soyuz have had, there could very
well be many of these sorts of issues that could cause a fatal disaster, but
we've just been lucky so far.

When we finally have a space transportation system that goes through maybe
10,000 flights with the same vehicle, then you can start building confidence
due to past success. You can't do that with a hundred or so flights of an
expendable vehicle or the same number of flights spread out over several
partially reusable vehicles.

Jeff
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