Its all the systems in the Shuttle that need to be kept going.
I doubt the technology will be there to get rid of those very soon, make
the bits certainly but its still going to need a lot of looking after.
Brian

--
Brian Gaff -
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
Blind user, so no pictures please!
"greenaum" wrote in message
...
On Sat, 18 Sep 2010 01:36:04 -0400, JF Mezei
sprachen:

Perhaps NASA might be able to develop a cost effective way to
manufacture large carbon-carbon parts and make a shuttle belly out of a
dozen carbon-carbon panels instead of thousands of tiles.

I realise this is nearly a year old, but Usenet's not what it used to
be...

The latest New Scientist is a bit of a special on 3D printing /
"additive manufacturing". At the moment, it's based round spreading a
layer of powder, and using lasers / electron beams to melt the powder
together, sintering it into solid parts. You do one layer, then spread
some more powder for the second layer. After a while, you end up with
a big pile of powder with a 3D object hidden in it.

Current materials for the powder include titanium and nylon. Parts can
be made much lighter, since the method allows literally any shape to
be made. Shapes that are impossible to cast or cut using tools. You
can save a huge amount of weight, and CAD's being able to do the
modelling to design strength and stress-resistance for decades now.

Anyway, the next medium-sized step is composites. Use different
materials in the layers, allowing complex compounds that behave very
differently to anything possible now. Things can be made at the
microscopic level, the idea is we'll soon be able to make materials
with any property you like, not just any shape. Things like a material
that gets thicker as you stretch it.

Give this a few more years, (and not that many!). Everything will be
changed, almost anything will be possible. What if a shuttle weighed
half as much? In the not-too-far future, perhaps one could make a
whole shuttle on a 3D printer. Give the print-heads the right
materials, and you could maybe even have the thing pop out complete
and almost entirely in one piece! Certainly a 1-piece or few-piece
heat shield is likely possible.

If you can ensure things are safer, and ideally simpler, that makes it
cheaper to ensure you probably won't kill too many crew members. Which
is a big expense.

Still, what's the most expensive part of running the shuttle? I'd
imagine it's the well-qualified staff that run everything on the
ground, and work for the contractors. And lots of investment in tools
and equipment. At least the latter can be replaced by this.

--------------------------------------------------------------------------------
"There's nothing like eating hay when you're faint," the White King
remarked to Alice, as he munched away.
"I should think throwing cold water over you would be better," Alice
suggested: "--or some sal-volatile."
"I didn't say there was nothing better," the King replied. "I said there
was nothing like it."
Which Alice did not venture to deny.