``We were sitting on the rim of the Grand Canyon with our feet dangling over the edge of the abyss, which might be an appropriate place to do something like that,'' says the 40-year-old Air Force lieutenant colonel.

His fiancee works at the Kennedy Space Center in Florida.

Halsell, who's from West Monroe, La., became an astronaut in 1990. This is his third spaceflight.

``It's an unparalleled event for the science community,'' she says.

Still is only the second woman to pilot a space shuttle.

She was encouraged to become a naval aviator and astronaut by shuttle commander Dick Scobee, who died in the Challenger explosion in 1986. NASA chose her as an astronaut in 1994, just two months before Eileen Collins became the first female shuttle pilot.

This is her second space trip; her first, of course, was in April.

The 35-year-old Navy lieutenant commander from Augusta, Ga., has flown F-14 fighter jets.

``Keeping a mental edge, from that perspective, was not a problem at all,'' she says.

Voss, 40, who has a Ph.D. in astronautics, worked for NASA and Orbital Sciences Corp. before becoming an astronaut in 1990.

This is her fourth spaceflight. As payload commander, she is in charge of all the science experiments.

She considers Rockford, Ill., home.

``With 24-hour-a-day science operations occurring over a 16-day period, we're more like a 10-kilometer race to get warmed up for the space station marathons that are coming right around the corner,'' he says.

Gernhardt, 41, a bioengineer from Mansfield, Ohio, was a professional deep-sea diver, developing space station tools for astronauts and robots, before becoming an astronaut in 1992. He has flown in space twice before.

He will be in charge of the shuttle while the pilots sleep.

Thomas, 42, a Cleveland native with a Ph.D. in materials science, worked for AT&T Bell Laboratories and Lockheed Martin Corp. before joining NASA as an engineer in 1988. He became an astronaut in 1990. This is his fourth spaceflight; he will conduct science experiments.

He typically manages shuttle missions from the ground.

``I don't think there's ever been a time when I hadn't wished that it was me up there instead of some of those guys,'' he says.

He grew up in Jamestown, Tenn.

Linteris, 39, works on advanced fire suppressants at the National Institute of Standards and Technology. He had to delay research back in the office because of this reflight.

He says he's accustomed to risk, even though he's not a career astronaut: ``Working in dangerous environments is something that all people who do combustion research are very familiar with.''