If all goes as planned, Dr. Thagard will break the American record for long-duration space flight and learn much during his three months aboard Mir about how humans adapt to weightlessness. No other American has ever before ventured aboard Mir, which for Dr. Thagard's benefit has been stocked with provisions like peanut butter.

Norman Earl Thagard was born July 3, 1943, in the small town of Marianna in the wilds of the Florida panhandle. Growing up in Jacksonville, smart, blue-eyed and self-disciplined, he showed a talent for technical subjects and graduated with bachelor and master of science degrees in engineering from Florida State University.

In 1966, he entered active duty with the United States Marine Corps, became a pilot, and soon found himself flying F-4 Phantom jets in Vietnam. He won 11 air medals for actions above and beyond the call of duty as well as the Navy Commendation Medal for valor in combat.

After his tour, he briefly served as a weapons officer with a Marine fighter squadron in Beaufort, S.C., before resigning from the military to teach and resume his academic studies. In 1977 he received a doctor of medicine degree from the University of Texas Southwest Medical School, and then interned at the Medical University of South Carolina.

The National Aeronautics and Space Administration snapped him up in 1978 as an astronaut candidate. On his first shuttle mission in June 1983 he conducted medical tests and collected data on physiological changes in astronauts. He also flew shuttle missions in 1985, 1989 and 1992.