On Fri, Dec 10, 2010 at 6:28 PM, spike <spike66 at att.net> wrote: > ... On Behalf Of Adrian Tymes >>If it's just a matter of exhaust velocity, what about ejecting stuff at > 100+ km/s? > > Sure, but where do you get all the energy? Bring a lightweight nuclear power plant? (Shielded from the exhaust, again.)