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.

Computers allow us to squeeze the most out of everything, whether it's Google looking up things, so I guess that tends to make us a little lazy about reading books and doing things the hard way to understand how those things work.

Globalisation means many other countries are asserting themselves and trying to take over leadership. Please don't ask Americans to let others assume the leadership of human exploration. We can do wonderful science on the Moon, and wonderful commercial things. Then we can pack up and move on to Mars.

Everyone who's been in space would, I'm sure, welcome the opportunity for a return to the exhilarating experiences there. For me, a flight in a shuttle, though most satisfying, would be anticlimactic after my flight to the moon. Plus, if I pursued a flight myself, people would think that was the reason I am trying to generate interest in public spaceflight. And that's not the purpose - I want to generate interest in long-range space exploration.

The big companies are the private industry. But they're faced with a short-term need to show a profit in short-term.

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'.

People communicate in Twittering ways. I've learned how to do that.