Newsgroups: sci.space.history
From: henry@spsystems.net (Henry Spencer)
Subject: Re: ISS on Saturn V (was Re: Follow Up program to Apollo)
Date: Mon, 25 Sep 2000 00:08:13 GMT

In article <20000924183656.23584.00000772@ng-fj1.aol.com>,
Hallerb <hallerb@aol.com> wrote:
>NASA was concerned enough about information loss that they videotaped a lot of
>the last shuttle being built, in case it  they ever decided to build another
>one or had questions about original assembly.
>Lots of details can get forgotten very easily...

Sometimes even videotaping isn't enough.  There was a short article in
Science a couple of years back, about a problem with the international
mass standard.  The standards for length, time, etc. are now defined in
terms that any capable laboratory can reproduce, but mass so far has
resisted all attempts at a universal standard.  The kilogram is still
defined in terms of a particular lump of metal kept in a Paris vault.

Although extensive use is made of secondary standards, so that wear and
tear on *the* kilogram is minimized, still it needs to be used from time
to time to check the secondary standards.  Before and after use, it has to
be cleaned, to keep atmospheric dust etc. from skewing results.  This is a
rather delicate job, to put it mildly; the slightest surface wear would
alter its mass detectably.

The measurement center in Paris has one guy whose ability to do this
ultra-fussy cleaning passeth all understanding.  He's *tried* to train
others to do it the way he does it, because he'll be retiring soon, but
nobody else does it nearly as well.  Videotapes, etc. have not helped, or
at least, not enough.  Nobody understands what he does differently that
makes him so much better.
--
Microsoft shouldn't be broken up.       |  Henry Spencer   henry@spsystems.net
It should be shut down.  -- Phil Agre   |      (aka henry@zoo.toronto.edu)