way-out idea

I think the technologies to do this are just about
there right now. Integrating them is going to be
tricky though.

Ok. I read in New Scientist recently about something that is
being researched- 3D printers.

Forget 3D images. A 3D printer is a descendent of the rapid
prototyping machines. It builds objects from combinations of
materials in carefully calculated positions, building it up
layer by layer, scanning the shape out with a nozzle that
squirts material out at the right moment. This allows a very
wide range of structures to be built.

Anyway what's the first thing you build when you get a
3D printer? Another 3D printer, naturally ;-)

It occured to me that a 3D printer is the main component
required for a Von Neumann machine. The main other
component being some way to manufacture silicon chips/
solar panels (fairly easy to do in a vacuum), purify
the necessary materials (not totally straightforward)
and mining (ditto).

In theory you could send a single Von Neumann machine out to
the asteroid belt, it would mine the asteroids, reproduce,
and then return home and jump straight into a hopper...

Anyway I think its a fun idea. Oh yeah and making
sure no 'mutations' occur is rather important...
(return of the killer robots isn't my idea of fun!)