NASA needs to focus on the things that are really important and that we do not know how to do. The agency is a pioneering force, and that is where its competitive advantage lies.

I was given permission to serve myself Communion, with wine and a wafer, on the surface on the Moon. But I was advised not to say anything about it at the time. Someone had strongly objected to the Apollo 8 crew reading from the Bible. We didn't want to get into any further trouble with the religious critics.

Most people never believed in the real possibility of going to the moon, and neither did I until I was in my twenties.

Space tourism is a logical outgrowth of the adventure tourist market.

Mars, we know, was once wet and warm. Was it home to life? And what can living and learning to work on its rust-colored surface teach us about the future of our own planet, Earth? Answering those mysteries may hold the key to our future.

The decision to go to the moon is now appreciated and associated with President Kennedy's speech, but somebody else had told him it was a good idea. It turned out to be a good commitment, but it was a unique situation.

Don't waste your time on beaming people up or down. Instead, consider gravity waves as advanced physics of the universe that could be used to travel interstellar distances.