Kalpana One design (was Rotating space colonies)

> > My understanding is that mass drivers require very large amounts of
> > energy and infrastructure, which might reduce delta-V energy costs,
> > but would likely explode the actual monetary budget.
>
> I don't think so. Energy's cheap on the Moon, at least during the
> day (or if you have a sub-sized nuclear power plant). And the
> infrastructure isn't much compared to what you'd need to process
> an asteroid. Mostly struts and coils of wire.

The kind of mass driver O'Neill promoted is of surprisingly modest diameter. The drive coils are only about the diameter of a dinner plate. The payloads being ejected are only about the size of a softball. So there's no reason to look at a mass driver as being this enormous infrastructure.

There's been later talk of much larger sized EM accelerators for launching tanks of liquefied oxygen from the moon. But we shouldn't let those much more ambitious proposals skew our perceptions of using mass drivers for lunar or asteroidal ore retrieval.

Regards,

Mike Combs