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.

Every success story is a tale of constant adaption, revision and change.

Virgin could never have grown into the group of more than 200 companies it is now, were it not for a steady stream of intrapreneurs who looked for and developed opportunities, often leading efforts that went against the grain.

THERE'S NO OTHER WAY to find out whether or not you'll be successful other than just doing it

I am impressed with just the enthusiasm for life and the fact that some of these people are in their 80's, even 90's, and they're absolutely determined to get out there and make a difference.

Not enough people realize the satisfaction you can get from really pushing yourself to the limits.

Travel the world and meet people. I've been fortunate enough to see so much of the world, and being able to do so has brought me so many wonderful friends and experiences. There is no better way to learn than exploring new places.