I agree with Peter Diamandis, the head of the X Prize Foundation, a charity that promotes the building of spaceships in the private sector, that George Bush’s push for Mars via the moon is outdated in its top-down approach (“Eyes on the Prize,” September 15, 2007). Encouraging the private sector in space exploration is the way to go. But the public sector should have a rôle to play in this endeavor, as well. In a collaborative effort, space agencies sponsored by the government would focus on those bits that the private sector cannot easily provide—mainly the infrastructure needed to lift things into earth orbit and high science. At the same time, the private sector would undertake much of the rest, especially where the risk involved is too great for the government to undertake. In an ideal world, top-down and bottom-up approaches to space exploration would mesh seamlessly. In the meanwhile, pushing the government in the right direction is an objective well worth the trouble, which is perhaps what the X Prize Foundation is also doing on the sly.