Earlier quoted context omitted.
> I know it's nearby on galactic scales but it's practically about 450,000 Earth years away with current technology :-) If we had the political will, the Orion design could get people there in, what, 200 years, and that's with '70s technology.
If I remember it correctly, the fast project would make 4 light years in ~150 years. So that would be 450 years (probably less, because it's on constant acceleration).
> If I remember it correctly, the fast project would make 4 light years in ~150 years.
133, but that's getting there as a missile (one-way acceleration, no turnover and decel to relative rest.)