Naveen Jain

I started off with a company, InfoSpace, with my own funding. The company was listed among the most successful companies and I went on to start Intelius and Moon Express. Now, I focus my time on using the skills of an entrepreneur to solve many of the grand challenges facing us in the areas of education, healthcare, clean water and energy.

How important is failure - yes, failure - to the health of a thriving, innovative business? So important that Ratan Tata, chairman of India's largest corporation, gives an annual award to the employee who comes up with the best idea that failed.

Supplying fuel for a Mars expedition from the lunar surface is often suggested, but it's hard to make it pay off - Moon bases are expensive, and just buying more rockets to launch fuel from Earth is relatively cheap.