re: #54 O say, does that Star Spangled Banner yet wave..

The current relative position of Mars puts it 11 minutes, 22 seconds of light speed from us. So not the farthest away but certainly far from the closest.

As for a manned mission to Mars, we are still so very, very, very far away from that. Aside from the logistics of feeding a crew for such a long journey, there would be concerns about the effects of such a long period in zero gravity and the prolonged radiation exposure.