New here, asteroids prefered

> > Stan Ulam
> > correctly deduced that a fast fission device- a bomb-
> > would be the most effective propulsion system for
> > spacecraft. That was in 1945 shortly after the first
> > one was lit off. It is still the only system that does
> > not waste almost the entire amount of energy being
> > produced. ISP for a Nuclear Pulse Propulsion system
> > would be in the thousands and most probably in the tens
> > of thousands.

This idea is a political non starter, no one is going to allow the setting of nuclear bombs in the atmosphere for a launch vehicle or allow the launch of vehicle with its fuel tank filled with nuclear weapons to (hopefully) go off in space.

Brooks