Strolling amid the stars

Veterinarian Richard M. Linnehan went out for a walk the other evening.

Make that way, way out — as in outer space, 200 miles above the Earth.

Better known to the world as a veteran astronaut than a DVM, Linnehan was the lead spacewalker on the U.S. Space Shuttle Endeavour's March journey to the International Space Station. The seven-man crew lifted off from Cape Canaveral, Fla., on March 11 to begin a 16-day mission, the second longest ever (Columbia's 1996 journey was one day longer). Endeavour was scheduled to return to the Kennedy Space Center on March 26.

This was Linnehan's fourth space flight. He flew his first space mission in 1996 and serviced the Hubble Space Telescope on his last flight in 2002.

During one of five spacewalks on this Endeavour mission, Linnehan and rookie Robert Behnken spent seven hours outfitting the space station's newly installed, 12-foot-tall Canadian-built robot, dubbed Dextre," with a set of tools and two cameras that will serve as eyes for the $209 million device so it can perform various future chores outside the orbiting station. Astronauts installed two 11-foot arms on Dextre during an earlier spacewalk.

Linnehan is "the Yoda of spacewalkers," says Endeavour pilot Gregory H. Johnson.

In the fourth of the five spacewalks, Behnken and astronaut Mike Foreman tested a high-tech caulk gun to see whether it and the substance inside it can be an effective means of repairing damaged heat shields on future shuttle flights, preventing the sort of heat-shield problem that caused the shuttle Columbia to disintegrate in 2003, killing the seven-member team.

The astronauts also dropped off and set up a storage compartment for a Japanese lab complex, named Kibo, that will arrive at the space station in May.

Linnehan, of Lowell, Mass., served as chief clinical veterinarian for the Navy's Marine Mammal Program in San Diego before completing astronaut training in 1992. He received his DVM degree from The Ohio State University in 1985 and is a member of the American Veterinary Medical Association, American Association of Zoo Veterinarians and International Association of Aquatic Animal Medicine. He is 50 and single.