Discovery

Astronaut Duane (Digger) Carey on what it's like to be in a space shuttle that is going through the atmosphere:

Because he is retired, Carey was free to speak more openly than an astronaut on duty.

He shared his experience in a space shuttle during landing.

Follow him into the pilot's seat:

An hour before the scheduled landing, rockets are fired for what NASA calls the de-orbit burn.

"You turn the orbiter around so that the rocket engines are pointing backwards, then you fire the rockets," Carey said.

"What that does is slow you down so you no longer have enough speed to stay in the Earth's orbit. You start to drop."

Thus begins a ride that trumps any state fair attraction.

As pilot of his mission, Carey was sitting in the cockpit next to Commander Scott (Scooter) Altman when they kicked out of orbit over the Indian Ocean, as the Discovery is scheduled to do before dawn Monday. They also flipped the orbiter, which had been flying upside down. They wanted its nose to be tilted slightly upward.

"It's a spectacular maneuver when you are sitting in the front seat," Carey said. "We got a great view of Australia as we were flipping around. ...I turned to the commander and said, "Scooter, nobody told me how cool this was going to be."

But what followed required all the composure Carey could muster. The orbiter still was flying more than 15,000 miles per hour and carrying kinetic energy from when rockets thrust it into orbit. Think of the energy in terms of the mighty clouds you see on a shuttle's liftoff.

"You essentially have 45 minutes to get rid of it during entry," Carey said. "You start the mission at rest, and you have to end the mission at rest."

A sea of colors

The big slowdown comes when the shuttle collides with millions of molecules in the Earth's atmosphere, which sets off a fiery exchange of energy. Between Hawaii and California, Carey watched the molecules explode into a glowing plasma that enveloped the spacecraft.

"It changed colors as you went along," he said. "It started out kind of whitish, then it got stronger and started to glow pink. Then orange. ... It seemed like it was never going to end."

Carey had seen it many times in simulations, but the real thing was eye-popping.

At one point, mission specialist Richard Linnehan, who was sitting near Carey, called out for him to look behind them.

"I adjusted my mirror so I could look out the back, and I saw great flashes of lightning off the back of the orbiter," Carey said.

As the plasma cloud generated electrical energy, it set off static flashes, he said.

"It was frightening," he said. "I was going, 'Man, I hope this thing holds together.' "

Looking forward again was not reassuring.

"The nose of the orbiter was glowing just as bright as a bright shining headlight, just beaming off into space," he said.

There was no actual headlight. Friction was heating the nose to a white-hot glow.

"I looked over to Scooter, and he says, 'What are you looking at?' " Carey recalled. "I said, 'I don't want to look out there anymore. It's too scary.' "

In eerie contrast, the inside of the orbiter was nearly silent, and the astronauts shot smoothly through the chaos surrounding them.

What seemed like an eternity lasted less than 15 minutes and the Columbia landed safely on March 12, 2002. A year later, it disintegrated on its way home from another mission, killing all seven astronauts.

From "Discovery's Risky Return" (Minneapolis Star Tribune, August 7, 2005), by Sharon Schmickle.