Re: Mars Colony?
I guess it's up to me to take the conservative view. Mars by Hohmann transfer orbit. Send an unmanned cargo ship first, then a large vessel, small crew - six months there, six months back, one year on site, in addition to scientific research they use that time to build a LARGE base, landing field and beacon. Next, build a large vessel that does nothing but travel in a Hohmann orbit between the Earth-Moon and Mars solar orbits (a cycler), and start up continuous population transfers.
Lower initial outlay than Mars Direct (though greater total cost, ameliorated over greater time), no political fallout from using nukes in space.