I believe that drudgery and clock-watching are a terrible betrayal of that universal, inborn entrepreneurial spirit.

A company's employees are its greatest asset and your people are your product

Have passion for what you do; believe in yourself and your product and your customer; persevere; delegate; listen. Have fun. Today, I add: "Do good".

My biggest motivation? Just to keep challenging myself

Life is a helluva lot more fun if you say yes rather than no

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 think entrepreneurship is our natural state--a big adult word that probably boils down to something much more obvious like playfulness.