AsterAnts

> Dear Folks,
> It is silly to say that a good machine shop can make their own tools,
> unless by tools you mean only those small pieces of metal that are used for
> cutting surfaces on, for example, a lathe. If you mean lathes, chucks, etc.
> this idea is wrong. Even drill bits. Why do shops order such items even
> when they have slack time? How would one make such machines in outer
> space?

A lot of things are cast. Casting isn't particularly difficult, but
there are economies of scale- you need quite a lot of energy to
melt metal and its cheaper in bulk. It's typical to only melt metal
once a week or so if you have the facilities and many shops don't
have the facilities. Solar ovens remove this scaling issue don't they?

Drill bits I'm not totally sure about, but I think they cast them,
and then sharpen using millstones. Clearly you need a less
malleable and more brittle metal for drill bits; the metallurgy is
important- carbon levels.

> Capturing small asteroids will never be cheep. Maybe if they are small,
> only small space craft will be needed, but those craft will need a lot of
> capabilities, engines (ion, sails, or other wise), to navigate (know where
> they are) to communicate and respond, to attach them selves and to do these
> things over the many years which will be required to get to a small asteroid
> and more years to bring something back.

Think about DS1, or NEAR. This isn't rocket science. Well, ok it IS
rocket science; but you're trying to make it sound super complex
when really it isn't. And they're really just remote controlled
bots they don't have to be AIs.

> It takes only a 2 or 3 days to go
> to the Moon, but perhaps 8 months to Mars, and this is a discussion of going
> a comparable or greater distance.

Yeah, but leaving the moon requires much more propellent. ION
drives only need tens of kilos of propellent, whereas the moon
needs more like equal propellent to the mass you are launching. And
the Russian Hall effect thruster ION drives can run on mostly
oxygen which is easy to separate from ore. I mean sure, if you've
got a mass driver on the moon, you're laughing, but that's a LOT of
work.