There may be aliens in our Milky Way galaxy, and there are billions of other galaxies. The probability is almost certain that there is life somewhere in space.

The way I see it, what is going to come out of the moon activities is a respect for U.S. leadership.

I don't think we're going to build a 50-person spacecraft or a 100-person spacecraft.

The first human beings to land on Mars should not come back to Earth. They should be the beginning of a build-up of a colony/settlement, I call it a 'permanence'.

I want to keep on the move, keep stimulated and challenged.

Before deciding what to do about national space policy, Obama set up an outside review panel of space experts, headed up by my friend Norm Augustine, former head of Lockheed Martin and a former government official.

It was challenging to understand what was necessary to successfully carry out all the training simulations that we, as crewmen, would experience, and make a very successful use of that training and education.