Newsgroups: sci.space.shuttle
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: gratuitous anthrophobia (was Re: Shuttle computer reprogramming)
Message-ID: <1988Oct30.005840.16683@utzoo.uucp>
Organization: U of Toronto Zoology
References: <6689@nsc.nsc.com> <6980@ihlpl.ATT.COM> <1938@kalliope.rice.edu> <1988Oct20.175844.24740@utzoo.uucp> <1356@thumper.bellcore.com <1366@thumper.bellcore.com>
Date: Sun, 30 Oct 88 00:58:40 GMT

In article <1366@thumper.bellcore.com> karn@ka9q.bellcore.com.UUCP (Phil Karn) writes:
>As for risky technology sometimes failing, that's precisely my point!
>When you take the low-cost, unmanned approach to spacecraft design,
>you can afford to lose on a few risks. 

Phil, can you explain to me why this is unique to unmanned spacecraft?
In fact, it's not -- low-cost slightly-risky approaches have been tried
on manned spacecraft as well, in non-critical roles.  (You wouldn't try
such a thing in Ariane's guidance system, would you?)

The crucial issue is not "unmanned" but "low-cost".  You can afford to
take risks, and hence learn something, only if the cost of a failure is
manageable.  What we need is transportation systems that give us more
opportunities of that sort.  In particular, we could use some *cheap*
launchers for really small payloads, maybe 50 kg or so.  Shared missions
generally involve a higher failure cost, since more than one payload is
at risk; we need launchers which we can afford to dedicate to one small
experiment.

>If you can't accept
>the consequences of a failure, you'd never try anything new.

Moreover, simply trying something is often a much better way to proceed
than trying to guess in advance whether it's going to work.  Obviously
one wants to try only things that look at least somewhat promising, but
studying the idea for ten years before trying it doesn't seem to do that
much to improve the chances of success.
-- 
The dream *IS* alive...         |    Henry Spencer at U of Toronto Zoology
but not at NASA.                |uunet!attcan!utzoo!henry henry@zoo.toronto.edu