From: Michael Lorrey (retroman@tpk.net)
Date: Thu Jul 17 1997 - 17:20:59 MDT
Mark Grant wrote:
>
> Michael Lorrey wrote:
> > As an indication of a plane truly mature for its flight regieme, take
> > any of the cessna singles for their maintenance requirements.
>
> Much of which (according to articles I've read by pilots) is imposed by
> the government and not really neccesary for safe operation. Even then,
> from reading some of Richard Bach's books, the amount of maintenance
> required to keep his biplane operational was far higher than that required
> for his jets, *and* it crashed more often.
I've never worked on a biplane, but I do know that business jets take a
good multiple of the maintenance time of small props planes. Rebuilding
a turbine engine is a lot tougher than a piston engine.
>
> > Sorry, the hard radiation of impacts and dopplershift would embrittle
> > the materials to a large extent.
>
> Isn't that what you have a shield there for? I mean, do you really believe
> that any alien race is going to travel from system to system in a
> spacecraft that will be considerably damaged by the mere act of travel?
You can sheild a large part of it, but you are going to preserve the
areas of greatest sheilding for your crew, and with a mid course
turnaround, you've gotta have two sheilds, unless you can unhitch from
it and turn around and rehitch to the sheild at midcourse.
You've also got to deal with the fact that your landing vehicles will be
stored out of their operating environment for several years. Unless you
set up a phased inspection dock in orbit to rebuild the lander before
entering atmosphere, you could have serous problems. For starters, all
gaskets, seals, tires and lamps will probably need replacement. All
systems will need full checkout, inspection, as well as xray inspection
for structural integrity. THis sounds difficult, but its not really,
with the one exception that you get no test flights....
>
> > How do you stop? SOrry, you've got to turn that mutha around and brake
> > for as long as you've been accelerating. That puts your ass end open to
> > reentry through an alien solar systems Oort cloud.
>
> Uh, yes. Just like reentry with the shuttle, only worse. This is why I
> think your figure of 0.98c is much higher than they're really use (and
> way off the scale for the kind of early mission they talked about).
I wouldn't go on a manned mission if it didn't utilize a goodly amount
of relativistic time dilation to shorten trip time for the crew.
Logistics are always the biggest ticket item on such a project, and the
longer your stretch it out the more you spend in magnitudes.
>
> > For starters, the shuttle orbits at a mere 17,000 mph, and it still
> > breaks down half the time, causing the mission to be cut in half.
>
> Firstly, note I said 'qualitatively', not 'quantitatively'. We all know
> that the shuttle is a massive boondoggle full of cut-price engineering and
> frankly I'm surprised it works at all. Even then it's only been called
> back early two or three times (not the 50% you mentioned) and the first
> time was an early test flight when things were expected to go wrong.
Well, it has some failure on it almost every mission. If the missions
weren't so short to begin with, such failures would be a serious
problem, witness the Mir.
>
> > You
> > can't do that on an interstellar mission. "Oops, Snorf, we busted the
> > toilet, we've gotta turn around...."
>
> When have NASA ever brought the shuttle back because of a broken toilet?
> AFAIR all those aborts were due to broken fuel cells, and the mission
> could have happily continued without them were it not for NASA's paranoia.
>
Once they brought it back due to a broken toilet. ANother time, they
overlooked the question of how the monkeys they had brought up were
going to defacate cleanly. They wound up with monkey shit all over the
shuttle decks.
The point is that things break more often than not with the shuttle,
even though it was custom built and is basically rebuilt after every
mission, and it only flies one week missions.
>
> But you're still talking about military aircraft, not commercial (and I'd
> agree that if this were the first flight that might be a valid comparison,
> I just don't think that it would be). And you're talking to someone who
> worked as a military avionics designer, so I know more than a little about
> the badly designed military maintenance programs that I talked about. I'll
> just get into trouble if I *do* talk about them.
>
> > There is nothing badly designed about them. They are doing their best
> > with what they can get.
>
> Precisely; and they could get a lot better for the same price, if they
> speced it right in the first place.
>
Specs are usually right on the money when they are developed, based on
the latest military theory (which may or may not be true, i.e. AA
missiles making cannon and dogfights obsolete). What happens is threats
change, so specs become obsolete.
>
> However, the people who were looking after the Blackbirds weren't those
> geniuses, they were just normal Lockheed technicians. The main differences
> (from what I've been told) were in training, motivation and longevity;
> the Lockheed crew were there *because* they wanted to work on those planes
> and stayed with them for years whereas the Air Force crew were just posted
> there and moved on a couple of years later.
A "normal" Lockheed technician is still much more highly trained than
the average service joe, and you are right, morale and motivation have a
lot to do with it, which brings up another possible cause of mission
failure on an interstellar flight: depression. From space station
experience we know that astronauts are at high risk for depression, and
those are mere 50-180 day missions. Imagine being cooped up in a can
with a couple other people for 5-10 years. What sort of slump in
maintenance do you think will occur?
The end of flight orbital insertion will then require a full phased
inspection and rebuild for the lander. THis is the point where slipups
are going to occur.
--
TANSTAAFL!!!
Michael Lorrey
------------------------------------------------------------
mailto:retroman@tpk.net Inventor of the Lorrey Drive
Agent Lorrey@ThePentagon.com
Silo_1013@ThePentagon.com http://www.tpk.net/~retroman/
Mikey's Animatronic Factory
My Own Nuclear Espionage Agency (MONEA)
MIKEYMAS(tm): The New Internet Holiday
Transhumans of New Hampshire (>HNH)
------------------------------------------------------------
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]+$y)%256;&S}$x=$y=0;for(unpack('C*',<>)){$x++;$y=($s[$x%=256]+$y)%256;
&S;print pack(C,$_^=$s[($s[$x]+$s[$y])%256])}sub S{@s[$x,$y]=@s[$y,$x]}
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