Thanks again, Randall Munroe

[deckardcanine]

While I'm still not convinced that there's much to be gained from attempting space colonization, I have arrived independently at his implicit conclusion:

Comments

[nefaria.livejournal.com]

There's a big problem with traveling to Mars: epic levels of radiation. You'd have to coat the spacecraft with a thick layer of lead to keep the people alive that long, and it'd be hard to get a ship like that off the ground from Earth, much less launch it back from Mars for the return voyage with no NASA station down there to help out.

[jordan179.livejournal.com]

You're assuming that an interplanetary spaceship would have to launch from the Earth. Why not build and launch it from Terrestrial or Lunar orbit, bringing the crew and supplies on board with shuttles? Furthermore, you're assuming that only matter-based radiation shielding is possible: if you are talking about charged-particle radiation, then magnetic shielding can also be employed.

[jordan179.livejournal.com]

Yes. People who insist that we solve all our problems here on Earth before exploring or colonizing other worlds are implicitly arguing that we should never explore or colonize other worlds, because we will never solve "all our problems" -- for the very good reason that, as we solve one set of problems, we discover a new set.

There is a subtler problem. There is no "we" who can decide for all Earthly organizations for all time. All that the leader of any Earthly faction can do is decide that they will or will not attempt to explore or colonize other worlds for the time of their dominance over their organizations. Other factions are free to continue such efforts, and factions in the future are unlikely to feel bound by prior decisions -- even of their own leadership.

All that a particular leader can decide is "My faction will reduce its influence over the future of other worlds -- for my lifetime."