Boldly going?

Could the first Mars colony be a retirement community? Lawrence Krauss thinks so:

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 Suns 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?

His solution: send older astronauts who can live out the rest of their lives on Mars.

I like the spaceship designs with the big sphere of water shielding, but it would be expensive such a mini-moon around the solar system if we’re stuck tossing combustion products out the backside. Meanwhile, we will be landing increasingly capable robots there – as Krauss notes, the “only humans can do it” angle is not very persuasive.

It’s not hard to imagine five or ten 70-year-old astronauts going to Mars permanently. Although, I’d go crazy if the Internet were on a variable delay of several minutes.

(via Althouse)