Steven Den Beste Strawman

>http://denbeste.nu/entries/00001113.shtml

excerpt:
"The L5 society originally suggested mining it on the moon and
shooting it towards Lagrange Point 5 with mass accelerators on the
surface of the moon. To mine and refine millions of tons of mass on
the moon would itself require a substantial moon colony. But that
whole concept ignores one basic problem: how do you stop those
capsules when they reach the L5 point? Momentum is always conserved;
you've got to get rid of it some way. For each ton moved to stable
orbit, you're going to require a lot of fuel for rocket engines to
slow the stuff down"

I agree that decelerating masses mined on the moon will need a lot of
energy. But building a habitat has not to depend on masses mined on
the Moon. Masses mined on asteroids will not carry this heavy
gravitation well ballast.

Ideally the habitat would be built near the asteroid which delivers
the most material. This building process would have be done through
robots and remote control.

Men have built the pyramids or the Chinese wall moving masses of
millions of tons, why couldnt engineers build a habitat with robots
which can move hundreds and thousand of tons in an low gravitation
environment?

The hardware needed would get constructed in LEO, for instance using
the ISS as a base for space construction.
The built hardware would than get sent by solar sail or ion propulsion
to the habitat construction site.

To build up an interplanetary communication satellite system for
remote control I would recommend my Solar Sail Launch System :-)
http://solar-thruster-sailor.info/figs/fig19-21d.html which provides
lots of energy for the craft to serve as communication relay.
This craft could carry also landers for first exploration missions on
asteroids.

On the other hand transporting material with solar sail propulsion and
also with ion thruster propulsion were a lot less of fuel is needed
because of the high exhaust velocities made possible through solar
electric acceleration would be a possibility to transport/decellerate
mass driver products of the Moon also.

Frank