WHEN I SEE the spaceship on the launch pad in a cloud of vaporized oxygen, I know that it's alive, that it's breathing. It's beautiful bathed in those xenon lights, white with that apricot-colored tank. The solid rocket motors, boosters, glistening because they're metal; and the rest of the shuttle a dull white against the black bottom tiles. I have seen it so many different times, but I never get tired of seeing it.

On this morning of our launch, I quietly slip to my knees and thank God for this opportunity, to have this experience, and I ask for a prayer of protection for the mission. Then I hear somebody yelling for me and it's time to get in the ship.

My pockets are crammed full of things. I have a voice-actuated recorder in my pocket by my left ankle. I have a pocket Bible on my right side. I also have the regular equipment: a pair of scissors, a knife, a little flashlight because sooner or later you're gonna need a flashlight. I have my Sony Walkman and I have a special tape that my little girl, Nan Ellen, made for her daddy, to sing to her daddy in space. And I have my wedding ring on.

The cockpit is very cramped. I climb in and crawl over to my seat, being very careful not to hit any switches. Then I lie down in my seat, on my back with my feet in the air.

I am strapped in with a harness, a prefitted one that has my name on it, with a chest belt and straps across the crotch. Built into the harness are two inflatable life preservers for flotation in case we come down over the ocean.

I recite the 23rd Psalm because that's the one that says, "The Lord is my shepherd, I shall not want. He maketh me to lie down in green pastures, He leadeth me beside the still waters, He restoreth my soul. Yea, though I walk through the valley of the shadow of death I will fear no evil. For Thou art with me. Thy rod and thy staff they comfort me. Thou preparest a table before me in the presence of my enemies. My cup runneth over. Surely goodness and mercy shall follow me all the days of my life and I will dwell in the house of the Lord forever." And that is appropriate to me because even though I know I am facing the valley of the shadow of death I have no fear.

At four minutes before launch I lower my visor. I reach back for a knob that tightens the entire helmet on my head so that when the visor goes down I've got a tight seal that prevents any oxygen from leaking out.

I am hearing constant talk over the headset in my helmet. Everybody is reading off data from the computers.

I feel the movement of the ship under me at around three minutes, when they check the flight-control surfaces, the flaps on the wings that control the ship. I can feel them moving as if it is an airplane, and I know that I am on top of a loaded and live space ship.

The count just flies by -- my memory of these last four minutes is a blur -- until we get down to 31 seconds. That is a major mark because then the onboard computers take over everything regarding the countdown. The automatic sequencing in the last 31 seconds is controlled by the four onboard computers, with a fifth serving as a backup.

I have my gloves on and I have turned the sleeve of my left glove back, so I can look at my watch -- it's a $19 Casio with a stopwatch, and it is set to zero. I am sitting here waiting, knowing that in seconds the three main engines in the tail of the shuttle are going to ignite. They are going to throttle up. If they don't throttle up properly, the computer is going to shut them down automatically before the solid rocket boosters ignite. Once the solid rocket boosters ignite -- that's it. You can't shut them off.

I know that one danger facing us is that the solid rocket boosters -- the two candlesticks on either side -- have to ignite at precisely the same moment. Because if they don't -- if there is as much as a second's delay -- we would have one thrusting and the other one still down, and we would have a cartwheel and a giant explosion.

The engines ignite. I feel a real surge of energy. But I'm still trying to pay attention because I want to activate this stop watch at precisely T-minus zero. That way when we go through the ascent I will know exactly what's happening to us, just by looking at my watch, since I know what is supposed to happen at each time of the flight.

I don't feel any movement yet away from the pad because we're still bolted down. I have been told there is a swing, but I can't feel it yet.

There is a roar of noise now. It's a roar. All I'm hearing is this roar. And there is a vibration, with the engines going and the ship still strapped down on the ground. To suppress the noise and the vibration, they are dumping thousands of gallons of water on the exhaust. Without it, the acoustic shockwave would be so much that it would destroy the shuttle.

I am still prepared, right down to T minus zero, for the possibility that we may have an engine shutdown and abort the mission. We have had two shutdowns before. And I am thinking that we could have another.

And then the thrust at T minus zero. It's a jolt. It's a roar. I punch my clock, pull my hands back into me, turn my head to the left, look out the window and all that I can see is gray. And that is the gray steel of the gantry. It takes us about seven seconds before we clear the tower.

It's a slow rise and there is a definite surge of energy and vibration. As we clear the tower I am still seeing the ground and the next picture that I have out the window, to my surprise, is not the ground but darkness and the lights of Cape Canaveral. That confuses me.

The commander is talking us through the liftoff. He's talking to us about everything that's happening. There go the engines, he says. Okay, the solid engines have ignited. We are climbing, we're clearing the tower. At about 10 or 11 seconds the pilot says we are starting our roll maneuver. And that's when I see light turn to darkness as the ship rolls over 90 degrees and my view turns from the bright morning sky to the ground. I stop looking out the window.

Something is wrong. I hear the pilot saying we have a malfunction. He is talking to us in the cabin on the intercom -- not to the ground -- and he's saying we've got a helium leak. He immediately jumps on it and starts explaining to us what he is doing. The pilot reconfigures some controls to stop the leak.

He doesn't even tell Mission Control about the leak until he has solved the problem. Then he tells them what the situation was.

It takes him 10 or 15 seconds to fix the leak. He has spent hundreds of hours in the simulator on the ground preparing for something like this, so he knows what to do.

The way it happens underscores that it's not the people on the ground who fly this machine, it's the commander and pilot. And they're doing it in real time because they've got the controls. Even though everything is programmed according to a computer, if something goes wrong, they've got to know what to do.

After 25 or 30 seconds of flight, they throttle the main engines back to 65 percent of power. They are throttled down that way for 10 or 15 seconds because of the air pressure that's building up. When they get past that dense atmosphere, they throttle back up to 104 percent. That's full power, about 75 seconds into the flight.

I don't hear or feel the throttling back. There is still so much noise at this point because of the solid rocket motors. You can hear them. It's only after they separate two minutes into the flight that it suddenly becomes quiet.

At this point I have the sense that this is a finely-tuned racing machine. It is obviously all working. This enormous surge of energy is hurtling us almost straight up. I am sort of in wonderment. I am going in a direction that I have never gone before, which is straight up. With all that energy at my back, and all that noise.