The Exploration of Mars by Humans: Why Mars? Why Humans?

As we commemorate the 50th anniversary of Yuri Gagarin's historic flight in 1961, the first flight of a human in space, plans are underway for another historic human mission. Plans are being developed for a human mission to Mars. Once we reach Mars, the human species will become the first two-planet species. Both the Bush Administration (in 2004) and the Obama Administration (in 2010) proposed a human mission to Mars as a national goal of the United States.