Jumping the Gun. Forum: Spacesettlers
Thread: Jumping the Gun.
# 5086 bymikecombs@... on March 15, 2004, 4:57 p.m.
Member since 2021-10-03
From: Karell Ste-Marie [mailto:stemarie@brain-bank.com]
to go that route why not use an "elastic-powered"
> catapult?
I'm skeptical that an elastic-powered catapult could be built which
could launch payloads to 2.4 km/sec. The nice thing about the mass
driver is that the coupling is magnetic, so we don't have to worry about
things tearing apart (or wheels flying apart, or sliding surfaces
heating, etc.).
My attitude is that back in the days when NASA had the money to spend to
assemble tiger team study groups to look at space industrialization, the
mass-driver emerged as the key to economical launch of raw material from
the moon. I'm disinclined to second-guess them. It's not even the case
that it's the first thing they looked at. They originally looked at a
rotary pellet launcher.
> I mean, it's not like you are going to get wind resistance on the
moon, why use something that will use up so
> much juice?
The requirement to launch a given kilogram from the moon at a certain
velocity involves a certain amount of kinetic energy. We will have to
pay for that energy, regardless of what method we choose. So the only
issue really is efficiency. Mass drivers, in terms of conversion of
electrical energy to kinetic, have quite high efficiencies.
Regards,
Mike Combs