RE: RE: RE: starship-design: Plasma Engine (VASIMR)

["L. Parker" <lparker@cacaphony.net>]

Kelly,

> I.E. the reactor fisionables are the fuel, and are heavy compared
> to fusion
> fuel to generate the same power.  This sounds like it would be
> pretty heavy
> compared to a direct fusion system.  I.E. all the fusion energy directly
> converted to exaust kinetic energy.

No, it still uses hydrogen as fuel. The reactor fissionables are actually an
insignificant part of the mass. Especially compared to the mass requirements
of a true fusion system. Think of the reactor and its fissionables as simply
being the "engine", a 40 kW reactor weighs only slightly more than the RTG
that powers Cassini.

Lee