Photos: Stephen Hawking's zero-gravity flight

For a short while on Thursday, physicist and author Stephen Hawking was up and out of his wheelchair-- and out of the grip of gravity. The weightless experience aboard an airplane in Earth's atmosphere underscored a point Hawking has been making in recent months: that the future of the human race is in outer space. Hawking called the experience "amazing," saying in a statement "I could have gone on and on--space here I come."

The flight took off from the space shuttle landing facility at NASA's Kennedy Space Center in Florida, under the auspices of a company called Zero Gravity. Zero-G's founder and CEO, Peter Diamandis (at right), is a prominent backer of commercial space travel and helps run the X Prize Foundation, which has broadened its scope beyond space ventures to other fields of science, from genomics to energy efficiency for cars. At left is astronaut Byron Lichtenberg.