Lawrence Krauss proposes that one way to be able to travel to mars would be a one way ticket.
The most challenging impediment to human travel to Mars does not seem to involve the complicated launching, propulsion, guidance or landing technologies but something far more mundane: the radiation emanating from the Sun’s cosmic rays. The shielding necessary to ensure the astronauts do not get a lethal dose of solar radiation on a round trip to Mars may very well make the spacecraft so heavy that the amount of fuel needed becomes prohibitive.
There is, however, a way to surmount this problem while reducing the cost and technical requirements, but it demands that we ask this vexing question: Why are we so interested in bringing the Mars astronauts home again?
I bet Adam would be willing. I’d be tempted.