Not the type of guy to be kept down

One of the world’s foremost scientists slipped the bonds of his wheelchair Thursday to float in zero gravity in the skies above the Atlantic Ocean.

Stephen Hawking, a renowned British physicist who has Lou Gehrig’s disease, experienced about four minutes of simulated weightlessness aboard a modified Boeing 727 jet operated by the Zero Gravity Corp.

The flight -- part philanthropy, part space tourism, part publicity stunt -- departed from the Kennedy Space Center’s shuttle runway with a throng of international media looking on.

Hawking, a professor at Cambridge University, is considered one of the world’s foremost authorities on cosmology and theoretical phenomena such as black holes. He is the author of the best-selling book “A Brief History of Time.”

At a news conference before taking off, Hawking said he wanted to demonstrate that anyone could take part in the experience. Unable to speak or move his limbs, he communicated with a computer-synthesized voice controlled by a headset that measured facial movements.

“I think the human race has no future if it doesn’t go into space,” Hawking said. “I have long wanted to go into space, and the zero gravity flight is a first step toward space travel.”

After the flight, Hawking suggested he was ready for more.

“It was amazing,” Hawking said.

“I could have gone on and on. Space, here I come.”

More than a dozen people accompanied the 65-year-old professor on the flight -- including four doctors and two nurses sent to monitor his health. Instruments measured Hawking’s blood pressure, heart rate, and oxygen and carbon dioxide levels.

After departing the space center eastward over the Atlantic Ocean, the flight climbed to 32,000 feet. Eight controlled dives created periods of weightlessness lasting 20 to 25 seconds each during the 90-minute trip.

Hawking was laid on his back on the floor of the aircraft. When the dives began, Zero Gravity Corp. co-founders Peter Diamandis and Byron Lichtenberg helped lift Hawking and hold him in position. During a couple of dives, Hawking asked the men to flip him around.

“He was doing gold-medalist gymnastics,” Diamandis said.

Hawking’s flight was the first for a disabled person.

Leaving nothing to chance, the same team did a practice run Wednesday with Ted Straight, a 14-year-old middle school student from Florida substituting for Hawking.

“Professor Hawking is about as determined as any individual on the planet,” said Dr. Edwin Chilvers, Hawking’s personal physician, “which is why we’re here doing this.”

Based in Florida and Las Vegas, Zero Gravity Corp. has flown more than 2,500 passengers on simulated weightless flights since October 2004. An excursion featuring 15 dives costs about $3,500 per seat.

The group flying with Hawking included eight people who bought seats at an auction to raise $150,000 for charity.