RE: starship-design: Mean Time Between Failure

["L. Parker" <lparker@cacaphony.net>]

On Friday, December 12, 1997 9:52 AM, Isaac Kuo [SMTP:kuo@bit.csc.lsu.edu] 
wrote:
> NASA and the military don't build things to last centuries, and have
> no incentive to do so.  (The former because nothing they build will
> be used so long and the latter because anything built today will
> be obsolete soon enough.)

Wrong.

>
> Building things to last is an engineering problem, and it can be done.
> Ask an engineer to design something that will last 100 or 1000 years,
> and he'll go and do it.
>
Wrong.

> The question is--why?  Why would you build something designed to last
> 1000 years without maintainance?  Well, Hoover Dam's massive turbines
> are an example of this.  There simply isn't any practical way to
> perform maintainance on them, so they and their bearings were designed
> to last 1000 years (this is undoubtably optimistic, and extrapolating
> far beyond any reasonable bounds, but at least they've done well for
> the larger part of a century).

Wrong.

>
> There really isn't a big secret to making things last--you keep them
> simple and big and heavy rather than miniaturized and pared down to
> minimum tolerances.  My dad's old Sony turntable and amplifier works
> perfectly after 3 decades because they just plain overengineered the
> things back then.  Advances in technology allowed miniaturizing,
> reducing wasted space, and paring down the thicknesses of the case
> walls to a minimum, so today's Sony amplifiers are more sophisticated,
> smaller, and lighter.  But I wouldn't be on them lasting as long.

Wrong.

>
> For today's space missions and military applications, of course, it's
> anathema to bulk up components without good reason.  Making them last
> more than a few decades isn't a good reason for a mission which lasts
> only a few years.

Wrong.

Go get a book and study mission operability and systems reliability. Or, 
(shudder) work in the field with these military and NASA systems that you 
seem to have personally designed and know all about their maintenance 
philosophy. I have, and you obviously haven't.

Lee