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.

A family needs to work as a team, supporting each other's individual aims and aspirations.

I believe that space travel will one day become as common as airline travel is today. I'm convinced, however, that the true future of space travel does not lie with government agencies -- NASA is still obsessed with the idea that the primary purpose of the space program is science -- but real progress will come from private companies competing to provide the ultimate adventure ride, and NASA will receive the trickle-down benefits.

Trips to Mars, the Moon, even orbit, will require that we provide astrotourists with as many comforts from home as possible, including paying each other.

It was designed to have an impact on the stalemate over Mutually Assured Destruction with the Soviet Union. Us reaching the moon convinced Gorbachev and other leaders that the Soviet Union couldn't compete with the U.S., so they revised their agenda. But people have short memories.

In Mars, we've been given a wonderful set of moons where we can send continuous numbers of people.

There's no doubt that there will be many trials and tribulations along the way in taming space for the benefit of all, unmasking its truths and using the boundless resources available to us. Taking a chance allows us to seek new horizons -- and we all benefit from being horizon hunters.