Engineer and daredevil explorer Bill Stone is obsessed with discovery. After years of crawling through the deepest unexplored caves on the planet, he’s building robots to go where he can’t. His company Stone Aerospace built DepthX, an autonomous robot, which descended 1,099 feet down Mexico’s deepest watery sinkhole. By 2008 he’ll send an enhanced machine through the ice of Lake Bonney in the Antarctic. But that’s just a test for the real mission, building a probe with Nasa to bore through miles of ice on Jupiter’s moon Europa, then swim through the buried Europan sea in search of alien life.

He’s also hoping to singlehandedly jump-start commercial human space exploration by offering spacefarers affordable fuels and consumables extracted from the moon. His new Shackleton Energy Company, or SEC, intends to raise $15 billion (as he points out, this is about the cost of a North Sea oil production platform complex) to mine ice thought to be trapped on the moon's southern pole at Shackleton Crater, and to sell derived products (including propellants and other consumables) on the moon and in low earth orbit (LEO) to international consumers. If all goes well, SEC will be open for business as early as 2015 as an international energy company.