Why do we need to solve the round-trip problem to Mars? Many set out in the past from the Old World to the New World with no intention of returning. There are

Why do we need to solve the round-trip problem to Mars? Many set out in the past from the Old World to the New World with no intention of returning. There are plenty willing in the near future to go one-way to Mars. "Humans in space" isn't about science ... robots do that. It's about pushing the limits of the human experience and spirit. http://www.nytimes.com/2009/09/01/opinion/01krauss.html http://www.nytimes.com/2009/09/01/opinion/01krauss.html ... send material and equipment to Mars first, then the first human colonists. To never return. It's 10% the cost of a round trip we can't afford.