Franklin Chang Diaz
Ad Astra Rocket Company, Webster, Texas

Even before he traveled into space as a NASA astronaut a record-tying seven times, Franklin Chang Diaz, 60, had already made a perilous and impressive journey. In 1968, at 18, Chang Diaz, unable to speak English, left his native Costa Rica and came to the United States with $50 in his pocket -- and a dream of becoming an astronaut. After a year of high school, he landed a scholarship to college; he went on to earn his doctorate in plasma physics from the Massachusetts Institute of Technology; then a 25-year stint at NASA followed. His research into propulsion systems for rocket engines eventually formed the basis of his company, Ad Astra Rocket Company, and Chang Diaz hopes it will lead to yet his greatest journey yet -- a manned space flight to Mars.

At the heart of Ad Astra is Chang Diaz's variable specific impulse magnetoplasma rocket, or VASIMR. In layman's terms, the VASIMR engine uses superheated gases known as plasmas to provide a highly efficient mode of propulsion for vehicles and cargo in space.

Ad Astra was formed in 2005, when NASA's Advanced Space Propulsion Laboratory, which Chang Diaz directed, was facing closure because of budget cuts. Rather than let a decade's worth of research go to waste, Chang Diaz urged NASA to let him privatize the operation. "It was amazing -- they actually said yes," Chang Diaz says. On June 23, 2005, the Advanced Space Propulsion Lab ceased to be, and the Ad Astra Rocket Company was born. NASA went so far as to allow the start-up to operate at the Johnson Space Center while Chang Diaz raised funds.

Within a month, Ad Astra had landed its first major investment of $6 million and soon set up a new lab outside Houston. The company is working on a joint mission with NASA to deploy a VASIMR engine to the International Space Station by 2014. Ad Astra also opened a second research facility in Costa Rica, where Chang Diaz has become something of a folk hero. In fact, about 50 percent of Ad Astra's funding comes from his homeland. "It's nice to see that there is no geographic monopoly on knowledge anymore," says Chang Diaz. "Space is now the realm of the whole planet, not just a few countries."