Lori Garver: Forget new manned missions in space. NASA should focus on saving Earth.

NASA was not created to do something again. It was created to push the limits of human understanding — to help the nation solve big, impossible problems that require advances in science and technology. Fifty years ago, the impossible problem was putting a human on the moon to win the space race, and all of humanity has benefited from the accomplishment.The impossible problem today is not the moon. And it's not Mars. It's our home planet, and NASA can once again be of service for the better