> No amount of cajoling, threatening or reasoning will get this guy to give up his "one-man island" philosophy.

That's an unreasonable assumption. If he doesn't breathe slowly, he dies. As CamperBob2 also points out, it would be completely irrational for the libertarian astronaut to refuse to cooperate, so he'd go along.

The problem most libertarians point out is that we're sometimes forced (by society) to contribute, without receiving anything in return. One-sided trades are the problem, not mutually-beneficial cooperation. When you pay 40% of your income so others get welfare, you're arguably not receiving anything in return.