WEIGHTLESSNESS ON EARTH--

The best way for astronauts to train for the weightlessness of space (zero gravity) is to be flown through a parabolic arc in a spacious aircraft.

When I did it years ago at Wright Patterson Air Force Base in Dayton, OH the air force used a modified version of a KC-135 tanker; a large, four engine jet aircraft.

Except for a few rows of seats, the cabin was stripped and the entire inside of the fuselage was heavily padded.

At an altitude of 30,000 feet the pilot would dive gradually to pick up airspeed. He would level, then under full power, climb; thus producing the up-slope of the parabola.

As the aircraft began to lose airspeed, he would gently push the nose over toward another dive, and, viola; weightlessness for about 30 seconds.

(Remember how your tummy feels funny when you drive fast over a small, elevated road surface, then sink on the other side. Same thing. Smaller scale.)

On the Dayton flight we sat on the padded floor in flight suits, holding a paper cup half full of water as the first climb began. As the pilot nosed over at the top of the arc, my body slowly floated off the floor of the airplane. I giggled.

At the same time little globs of water floated out of the cup and simply drifted with me as I did random, mid-air pirouettes. I giggled some more.

I had complete control of hand and leg motions, but, absolutely no control of my body as it gently caromed off other participants or various parts of the airplane interior. I felt like a pin ball in slow motion.

Then, a bell would ring, warning participants to attempt to get close to the floor as the parabola was concluding. One way or another, on the floor was where you would be seconds later.

Still giggling.