G. David Low, 52: Cerebral Astronaut Flew on 3 Shuttles

From 1980 to 1984, he worked at the Jet Propulsion Laboratory in Pasadena, Calif., where he was involved in preliminary planning for several planetary space probes. He also helped with the systems engineering design of the Galileo probe, a $1.4 billion spacecraft launched from the shuttle Atlantis in 1990.

He was selected as a NASA astronaut in 1984 and at age 28 was the youngest in his class. After a one-year training program, he worked on the shuttle's robot arm system and on plans for future spacewalks. He also served as the spacecraft communicator, or "capcom," for three shuttle missions, including the first flight after the loss of space shuttle Challenger in 1986.

"He was more academic than the rest of us," Culbertson recalled, "but he also became a very good operator. He was good with his hands, a good mechanic who worked on cars, but he understood the physics behind everything. He was also a good communicator."

On his first spaceflight -- the one with the antique socks stowed aboard -- he helped retrieve a science satellite called the Long Duration Exposure Facility. The 10 1/2 -ton satellite, the size of a school bus, was in danger of plunging to a fiery destruction, taking with it six years of valuable scientific information from nearly 57 experiments. Crew members filmed their activities for a 1994 IMAX feature, "Destiny in Space."

On his second flight, in 1991, Mr. Low assisted with the launch of the fifth Tracking and Data Relay Satellite and helped conduct more than 30 experiments related to plans for the future space station.

He continued working for NASA for three years after his last flight. Based in Crystal City, he served on the Russian Integration Team that worked out changes between Space Station Freedom and the international space station programs. He also assisted NASA's Legislative Affairs Office.

A Sterling resident, he joined Dulles-based Orbital Sciences Corp. in 1996, serving as vice president of safety and mission assurance for the company's Launch Systems Group. In 2006, he became senior vice president and program manager for the company's Commercial Orbital Transportation Service program.

Survivors include his wife of 15 years, JoAnn Andochick Low of Sterling; three children, Maggie Low, Christopher Low and Abigail Low, all of Sterling; his mother, Mary R. Low of Bethesda; two brothers, Mark Low of Woodinville, Wash., and John Low of Rockville; and two sisters, Diane Low Murphy of Bethesda and Nancy Low Sullivan of Rye, N.Y.