[Milsurplus] Cable lacing
mikea
[email protected]
Sun, 11 Apr 2004 14:34:48 -0500
On Sun, Apr 11, 2004 at 01:21:34PM -0400, J. Forster wrote:
> David Stinson wrote:
>
> > J. Forster wrote:
> >
> > > Lacing has NOT been used in space programs from at least the late 60s. The cord is
> > > springy and Teflon insulation cold flows in space vacuum, causing shorts in cable
> > > bundles.
> >
> > Interesting. Did they find that out on Gordon Cooper's Mercury flight
> > when all his systems shorted out?
> > What kind of insulation do they use?
> >
>
> I don't know. I only worked on unmanned missions. After the Apollo fire, they switched
> from Teflon to Kynar (polyamide) as I remember. On one instrument, we removed all the
> lacing and re-did the cables.
I strongly suspect that NASA didn't prohibit lacing until after the
Apollo I fire. I worked that mission (and all the others, boilerplate
and manned) from the last Mercury. I remember several debriefing tapes
on which crew had complaints about the electrical systems -- and other
complaints as well. One of the funniest was a Gemini mission in which
the crew had had dried apricots as part of 4 consecutive meals. They
described in considerable detail the effects on the atmosphere, and
just how very primitive the toilet arrangements (plastic bags with
adhesive around the rims) were.
And I was the guy who first ran the Apollo I biomed data off the tapes
and onto stripcharts for the docs at the MSC. That made an impression
on me that, I expect, will not fade as long as I love.
My strong suspicion is based on NASA's subsequent and repeated
failures to learn from past problems and from the repeated complaints
about electrical problems in earlier spacecraft. None of it is _proof_
and I don't expect that we ever can _know_, but I saw enough instances
of people being unwilling to see their noses in front of their faces
that I think this is a result of another such refusal.
--
Mike Andrews
[email protected]
Tired old sysadmin