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.

To be a real entrepreneur you always have to be looking forward. The moment you rest on your laurels is the moment your competition overtakes you.

Running a business is making a difference in people's lives

As much as you need a strong personality to build a business from scratch, you also must understand the art of delegation. I have to be good at helping people run the individual businesses, and I have to be willing to step back. The company must be set up so it can continue without me.

Those people who spend their time working on things they love are usually the ones enjoying life the most. They are also the ones who dared to take a risk and chase their dreams.

To be a great leader, you must be a great listener

Business opportunities are like buses, there's always another one coming.