+1 to Willi there, moon colonies are not currently "doable". They will be once we have on-orbit re-fueling. That is because you have to have some way of transporting things you cannot get or make on the moon, too the moon.
The Apollo program, as impressive as it was, was never expected to be extendable to a colony effort. Rather first a space station was to be put in orbit, then on-orbit refueling, then space 'tugs', and then you could send up things that could land on the moon and ship additional building materials there.
That said, I found the hovercraft idea interesting since the benefit of hovercraft are completely negated by the inability to push against the surface for turning force and thus to re-capture forward energy into turning energy. This is a huge problem with lighter than air airships as well. Asimov should have known that.
The Apollo program, as impressive as it was, was never expected to be extendable to a colony effort. Rather first a space station was to be put in orbit, then on-orbit refueling, then space 'tugs', and then you could send up things that could land on the moon and ship additional building materials there.
That said, I found the hovercraft idea interesting since the benefit of hovercraft are completely negated by the inability to push against the surface for turning force and thus to re-capture forward energy into turning energy. This is a huge problem with lighter than air airships as well. Asimov should have known that.