Obama sets goal of establishing a Mars habitat

President Barack Obama has set a goal of sending humans to Mars by the 2030s and getting them safely home again.
But that's not his only goal.
In a commentary appearing on CNN.com, Obama set an ultimate goal of setting up a habitat on Mars so astronauts can live there for an extended time.
"When our Apollo astronauts looked back from space, they realized that while their mission was to explore the moon, they had 'in fact discovered the Earth,' "Obama wrote. "If we make our leadership in space e