Weightlessness of space could offer freedom from infirmity
By Ben Bova

Sunday, March 18, 2007

The world’s leading expert on gravity is coming to Florida to experience weightlessness.

Stephen Hawking, the celebrated theoretical physicist who deals with black holes and cosmic gravitational fields, plans to fly on a Zero Gravity Corp. plane that gives its passengers a few moments of zero gravity.

Why?

Hawking is the author of the hugely popular book, “A Brief History of Time.” He is almost totally paralyzed, a victim of amyotrophic lateral sclerosis (Lou Gherig’s disease). Why does this wheelchair-bound intellectual want to take a flight on what is popularly dubbed “the Vomit Comet?”

Zero Gravity Corp., headquartered in Fort Lauderdale, is a company devoted to space tourism and entertainment. Its jet airliner flight takes off and lands at the Kennedy Space Center in Cape Canaveral.

To produce a feeling of weightlessness, the plane flies a parabolic arc, like the topmost section of a roller coaster. In the few seconds at the top of the arc, everything inside the airliner is effectively in zero gravity. People and objects float up off the floor.

On most of these flights the plane goes up and down several times, running from zero gravity to normal or even heavier than normal gravity. People get queasy, especially after a half-dozen or so such ups-and-downs. Hence the nickname, “the Vomit Comet.”

Why does Hawking want to experience a zero-G flight?

In a statement issued to the news media, Hawking wrote, “As someone who has studied gravity and black holes all of my life, I am excited to experience first hand weightlessness and a zero-gravity environment.”

But there’s more to it than that.

Hawking has been confined to a wheelchair for most of his life. His paralysis is so profound that he can’t even speak normally: He uses a computer’s synthesized voice to speak for him. But on that jetliner flight, for a few moments he will be free of the wheelchair that he needs on Earth.

And therein lies one of the most human, and humane, benefits of space flight.

All our lives we exist in Earth’s gravity field. We take it for granted. We weigh ourselves. We know that if we drop a glass from our hands it will fall to the floor and smash to bits.

Gravity pulls at us every moment of our lives. It tires us when we walk or play. In time it makes our faces sag, our bodies bend. Our backs and knees and hips wear out because they must carry the load that gravity imposes on us. In the long run, gravity kills us.

Yet just a hundred miles away, up in orbit, the effects of gravity are canceled. Weightlessness prevails. Astronauts and cosmonauts have spent months in orbit, living without weight. One of them told me after returning from nearly three months on the Skylab space station that his biggest problem readjusting to Earth was to remember that when he let go of something, it didn’t float weightlessly, it crashed to the floor.

Much has been written about the physical effects of prolonged weightlessness. Your body’s muscles atrophy, because they’re no longer working so hard. That includes your heart, the muscle that pumps blood through your body. In orbit, your blood is weightless, too. Your bones produce less calcium, because they no longer sense the stress that gravity produces.

These are problems when you return to Earth and your body has to deal with gravity again. But while you’re in weightlessness, your body is adapting to the conditions in which you find yourself.

What if you don’t return to Earth? What if you stay in space for good?

There’s a new industry being born: space tourism. Zero Gravity Inc. is one of several companies that are beginning to offer flights that will give passengers the experience of zero-G, even if only for a few moments.

Carry that idea one step further.

Eventually there could be a retirement industry in space. People who are too frail and feeble to live painlessly in the gravity of Earth may retire to places where the gravity is easier to handle.

The zero gravity you can achieve in orbit around the Earth isn’t the only possibility. If you lived on the moon you’d exist in a gravity that is only one-sixth that of Earth. A person who weighs 150 pounds on Earth would weigh only 25 pounds on the Moon. Everything else would also weigh one-sixth of its Earth weight.

The moon’s gentle gravity might be ideal for retirement. Zero gravity has its benefits, but it also has its complications. One-sixth G is enough to keep things in place and give you a firm sense of up and down.

Think of the athletic feats you could perform when everything weighs only one-sixth of Earth normal. In an enclosed space filled with air at normal pressure, you could strap on a pair of plastic wings and fly like a bird, on nothing more than your own muscle power. Think of tennis or golf on the moon, under protective domes filled with air so you could move about in shirtsleeves.

In the moon’s low gravity, even I might be able to dance like Fred Astaire.

The Hungarian recipe for an omelet begins with, “First, steal some eggs.” To get to the low-gravity environments of space you have to fly out of the high-gravity environment of Earth. When NASA’s space shuttle lifts off its crew is subjected to three times normal gravity for several minutes.

We would need gentler and safer launch vehicles to carry retirees to the low-gravity environments of space. But once there, a truly new world could open up for those who are too frail or too infirm to live on Earth.

The old adage is wrong: The meek will inherit not the Earth, but the gentler low-gravity environments of space.

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Naples resident Ben Bova is the author of more than 115 books, including “The Sam Gunn Omnibus,” a collection of short stories about a pioneering space entrepreneur (and rascal). Dr. Bova’s Web site address is www.benbova.com.