We should be pushing our boundaries. After all, we Britons are explorers and adventurers.

I get standing ovations at meetings when I say Britain should be involved in human spaceflight. Unfortunately, that goal has been blocked by a handful of people in high office.

You don't go into space just for the science. Economically, it is not worth it. I think the reason we should be in space is for the exploration; it's the human endeavour.

Is a one-way trip to Mars ever really seriously going to happen? Surely that's morally reprehensible. However old people are, however much they say they want to go on a one-way mission, people should be thinking about the possibility of returning.

Because we were orbiting the earth faster than earth spins on its axis, we went around the earth 16 times a day, an earth day, which meant 16 periods of lightness and 16 periods of darkness in 24 hours. Every so often you'd look towards the earth, and often you could see lightness and darkness together, and dawn and sunset were spectacular.

I had been lucky that my physiology is well suited to space training.