One thing Aldrin made clear in his Q&A session is that he wants to colonize Mars -- which means some travelers won't be coming home. "I think it's better to do [let people live there permanently] than to go through the expense of having people there for a year and a half, two years and then bring them home," Aldrin said. "Especially if they have prepared to and made the decision, have the willingness and desire to go and spend the rest of their lives there, pioneering." Aldrin specifically said he hopes that colonizing Mars can become a national objective. "I think the objective is to expand the human race outward, and [Mars is] the most likely place to set up permanently."