CAPE CANAVERAL, FL - APRIL 8: In this handout provided by the National Aeronautics and Space Administration (NASA), SpaceX's Falcon 9 rocket makes its first successful upright landing on the 'Of Course I Still Love You' droneship on April 8, 2016 some 200 miles off shore in the Atlantic Ocean after launching from Cape Canaveral, Florida. (Photo by NASA via Getty Images)

Elon Musk

By the age of 31, the South-Africa born Elon Musk had cofounded and sold two companies for hundreds of millions of dollars. One of them was Paypal. The other was SpaceX, the first privately run company dedicated to space exploration. Musk may be best known for his Tesla company and the Hyperloop, but he's most interesting because he's unpredictable.