Profile of Columbia's Laurel Clark

Laurel Clark was a mother, a diving medical officer, a flight surgeon and an astronaut who was well aware of, but undaunted by, the dangers involved in space travel.

"There's a lot of different things that we do during life that could potentially harm us and I choose not to stop doing those things," she said.

Clark, 41, was born in Iowa but considered Racine, Wis., to be her hometown. She told the Milwaukee Journal Sentinel that in high school she was a "boring straight-A student" without many hobbies, although she was a member of her school's swim and ski clubs.

Clark's professional career was an adventurous one, even before she became a NASA astronaut in 1996. She earned a degree in zoology from the University of Wisconsin-Madison in 1983 and then received her medical degree from the same school in 1987.

She used her degrees both underwater and in the air as a submarine medical officer and a flight surgeon. She had joined the Columbia mission to help with science experiments and had been one of the "guinea pigs" for the crew, providing blood, urine and saliva for onboard experiments.

Motherhood Was ‘Most Important’

Clark had to wait quite a long time for the Columbia mission. When she was assigned to the STS-107 mission in 2000, the launch was planned for June 2001. But a series of unrelated delays postponed Clark's flight again and again.

Clark was married with an 8-year-old son and as she told an interviewer before her flight, "Motherhood's been incredible, and I tell my son all the time that my most important job is being his mother."

Clark lost her cousin, Tim Haviland, in the 2001 attacks on the World Trade Center. Despite this devastating loss, she said her family was not concerned about terrorism during her space mission and they were very practical when putting risks into perspective.

"I think my family has a fairly practical and pragmatic view of this whole thing, and that's that the actual launching into space is much more dangerous than any of the other security concerns," she said.

Her late cousin's parents said last month that they had received an e-mail from Clark and reported that she was having a great time, but was also keeping an eye on home.

As her aunt Betty Haviland reported last month, "She was thrilled, taking lots of pictures, she could see the area in Wisconsin where they had lived for several years."