And Mars! One does not have to look far at all to discover that it is, using any known technology, impossible to get humans to Mars and back in one piece. Bone degeneration being one of the more serious problems. Mental degeneration being not allowed for discussion. The risk equation not working out another problem.
Robots.
And again, robots are great for scientific exploration, but don't put people on Mars, and if your goal is to put people on Mars, then sending robots there will only help so much.
An argument for a one-way mission, I suppose.
