Futudirection for Humanity? (was Don Davis article)

On 4/15/06, sraj wrote:
> Lucio mentioned use of:
> nuclear-powered
> > fully-reusable launchers (now that the anti-nuclear green movement
> > hopefully is starting to decline)
>
> ... Is such a rocket possible? I would have thought that it would be
> difficult to design a nuclear rocket for launch from Earth, due to the huge
> energy requirement in a very short time. An atomic explosion being ruled
> out!
(...)

Well, the Orion (http://en.wikipedia.org/wiki/Project_Orion) did not
rule out explosions and it seemed quite feasible technically.

However, I would rather prefer a nuclear gas-core reactor rocket
(http://en.wikipedia.org/wiki/Gas_core_reactor_rocket), which seems
more scalable and maneuverable, besides having no radioactive
"exhausts".