Re: Is this a new cheap way to get material into space?

From: Adrian Tymes (
Date: Thu Mar 01 2001 - 21:00:31 MST

Anders Sandberg wrote:
> "BillK" <> writes:
> > This 'mass driver' type machine only fires pellets at present and seems to
> > be intended as a weapon. But it can fire projectiles faster than escape
> > velocity with relatively gentle acceleration, so, if they increase the
> > projectile size big enough to be containers, why not use it to resupply
> > space stations? Lots of small containers soon equal the payload of a
> > resupply rocket.
> This has been studied, and I think there are some fairly detailled
> plans for how massdrives could be used made up by NASA and others.
> The problem is of course atmospheric drag and friction. Ideally you
> would like to have a nearly evacuated tube for the cargos to rise in.

Hmm...if you could make the mass driver and power supply light enough
(a significant challenge, no doubt),
what about doing the reverse? That is, fire your pellets away from
the direction you wish to go, fast enough and with enough drag that
they would vaporize before coming into contact with anything, and use
the recoil as lift. Once in orbit, make sure you're firing them such
that they come out at much less than orbital velocity, and drop down
into the atmosphere (with same result). Or, maybe let the pellets
vaporize from force of acceleration just before exiting the rail gun,
leaving only a trail of hot gas (just like chemical rockets). You'd
have to have a cycle time of much more than one a second, of course,
but the fire time in the article suggests potentially millions per
second, if desired.

Standard Idea Question: So, what obvious fallacy am I missing in the
above? ^_^;

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