Xref: utzoo sci.space:6208 sci.space.shuttle:913
Newsgroups: sci.space,sci.space.shuttle
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: Von Braun quote
Message-ID: <1988Jul22.211430.9898@utzoo.uucp>
Organization: U of Toronto Zoology
References: <1988Jun17.053132.5314@utzoo.uucp> <3361@phri.UUCP> <1988Jul10.003611.16575@utzoo.uucp> <1219@thumper.bellcore.com>
Date: Fri, 22 Jul 88 21:14:30 GMT

In article <1219@thumper.bellcore.com> karn@thumper.bellcore.com (Phil R. Karn) writes:
>Henry, I'm impressed. You *have* been reading up on us, haven't you!

No, actually, I was on the net and watching the Amsat news when it first
happened...

>But since you like to quote anecdotes, let's pick the Solar Max rescue
>mission. Remember how George ("Pinky") Nelson grabbed one of the solar
>arrays in an attempt to stop the satellite from spinning? ...

Phil, I didn't say humans were immune from stupidity.  Especially since
the instructions for that EVA specifically said "hands off the solar
arrays"!  Note that a similar, but slightly better thought-out, method
worked perfectly for the Leasat repair.

>... And I won't even mention the strong likelihood that
>the rescue mission cost more than a simple replacement would have.

Sure sounds to me like mentioning it... :-)  The economics of many of
these things are sensitive to what assumptions one makes about launch
costs.  One would hope that people saying "humans in space aren't worth
it" would preface it with "at current launch prices"... but they don't.
Do remember that the Solar Max rescue mission wasn't a dedicated shuttle
flight; the reason they had practically the entire payload bay empty was
the LDEF deployment.

>I've never understood why it's so necessary to put humans into space in
>order to benefit from their ability to react to unforseen circumstances.

It isn't necessary, it just helps a lot.  Teleoperation has some -- not
all, but some -- of the same limitations as automation.  Especially since
really general-purpose waldos are still in a very primitive state.

>[The human crew] need not be
>prime physical specimens; they can be chosen solely for their technical
>skills and perhaps even their understanding of the basic physics of
>rotating bodies (unlike Pinky Nelson).

This problem is already mostly licked, since the shuttle's acceleration
is deliberately held down to the point where any healthy adult could fly
on it.  This was a specific design goal, as I recall.  Don't confuse silly
NASA policies with fundamental hardware constraints.

>Your arguments represent a convincing case for versatile remote control,
>not for manned spaceflight...

I would agree, were it not that I know of no remote-control hardware that
I would call "versatile".  Remote control is great if the problems you
run into are along the lines that the designers anticipated.  The Voyager
team has done minor miracles with remote control... but considering how
badly Voyager 2 is limping, I suspect any of them would sacrifice one or
two semi-essential parts of his/her anatomy to get a repair technician
out to V2 for six hours.

>[AO-10] With the help of a versatile on-board computer
>that can be completely reprogrammed from the ground,  we were able to
>save the mission.

Correct me if I'm wrong, but as I recall the operative words were "save
the mission", as opposed to "carry out the mission as if nothing had
happened".  You did have to accept some penalties, did you not?
-- 
Anyone who buys Wisconsin cheese is|  Henry Spencer at U of Toronto Zoology
a traitor to mankind.  --Pournelle |uunet!mnetor!utzoo! henry @zoo.toronto.edu