Zero Gravity Corp. via AP file
Astrophysicist Stephen Hawking floats on a zero-gravity jet in April of 2007. The modified 727 carried Hawking, a handful of his physicians, nurses, and dozens of others on eight parabolic dips.
Science Museum handout via Reuters
Physicist Stephen Hawking is seen in his office at the University of Cambridge in December.
April 26, 2007: Stephen Hawking leaves his wheelchair behind to experience the effects of zero-G. NBC's Tom Costello reports.