There is no point in starting your own business unless you do it out of a sense of frustration.

My very first venture was a national student magazine to try to campaign against the [Vietnam] War. And so I wanted to be an editor. I wanted to bring the magazine out. And in order for the magazine to survive I had to worry about the printing and the paper manufacturing and the distribution. And, you know, I had to try to, at the end of the year, have more money coming in than going out.

I've used the Phoenix Centrifuge to replicate what the body's going to go through on the flight up. I've also done some gravity tests with ZERO-G [a charter-flight service in Arlington, Va., that uses modified Boeing 727s to simulate weightlessness], which went great.

I never set out to be a businessman

Too many companies want their brands to reflect some idealised, perfected image of themselves. As a consequence, their brands acquire no texture, no character and no public trust.

I have learnt so much over my 40 years of business which would have been valuable to me when I was younger.

If we can just get young people to do the same as their fathers did, that is, wear condoms