Walheim was commissioned as a second lieutenant in the Air Force in May 1984. In April 1985 he was assigned to Cavalier Air Force Station in Cavalier, North Dakota, where he worked as a missile warning operations crew commander. In October 1986, he was reassigned to the Johnson Space Center, in Houston, Texas, where he worked as a mechanical systems flight controller and was the lead operations engineer for the Space Shuttle landing gear, brakes, and emergency runway barrier. Walheim was transferred to Headquarters Air Force Space Command in Colorado Springs, Colorado, in August 1989, where he was manager of a program upgrading missile warning radars. He was selected for USAF Test Pilot School in 1991, and attended the course at Edwards AFB in California in 1992. Following graduation, he was assigned to the F-16 Combined Test Force at Edwards where he was a project manager, and then commander of the avionics and armament flight. In January 1996, Walheim became an instructor at USAF Test Pilot School, where he served until he began astronaut training.
NASA career
Walheim served as a flight controller and operations engineer at the Johnson Space Center from October 1986 to January 1989. He was selected by NASA as an astronaut candidate in March 1996 and reported to the Johnson Space Center in August 1996. Having completed two years of training and evaluation, he was qualified for flight assignment as a mission specialist. Initially, Walheim was assigned technical duties in the Astronaut Office Space Station Operations Branch. Walheim flew three flights, STS-110, STS-122 and STS-135, the final flight of the shuttle, logging over 566 hours in space, including over 36 hours and 23 minutes of EVA time. After his first flight, he was assigned to the EVA branch, where he served as the astronaut office representative for the Extra Vehicular Mobility Unit. In September 2002, Walheim served as an aquanaut on the joint NASA-NOAA expedition, an exploration research mission held in Aquarius, the world's only undersea research laboratory, four miles off shore from Key Largo. Walheim and his crewmates spent five days saturation diving from the Aquarius habitat as a space analogue for working and training under extreme environmental conditions. The mission was delayed due to Hurricane Isadore, forcing National Undersea Research Center managers to shorten it to an underwater duration of five days. Then, three days into their underwater mission, the crew members were told that Tropical Storm Lili was headed in their direction and to prepare for an early departure from Aquarius. However, Lili degenerated to the point where it was no longer a threat, so the crew was able to remain the full five days. During the inauguration of Barack Obama on January 20, 2009 in Washington, D.C., Walheim marched in the parade carrying an American flag and wearing a prototype of NASA's next generationspacesuit.
STS-110
Walheim served as Mission Specialist 1 on STS-110. STS-110 delivered the S0 truss segment to the International Space Station. Walheim conducted two spacewalks to install the S0 truss and reconfigure Canadarm2 for use on S0, spending 14 hours and 15 minutes outside the ISS. STS-110 lasted 10 days, 19 hours, 43 minutes and 38 seconds.
STS-122
Walheim served as Mission Specialist 2 and was the flight engineer for STS-122. STS-122, which was a 12-day, 18-hour flight, delivered the European-built Columbus module to the ISS the European Space Agency. Walheim conducted three spacewalks, totaling 22 hours and 8 minutes.
STS-135
Walheim served as Mission Specialist 2 on the final flight of the Space Shuttle, STS-135, a thirteen-day mission to the International Space Station. The mission launched on July 8, 2011 and landed on July 21.
Personal
Walheim is married to Margie Dotson, formerly of Villa Park, California. They have two children. He enjoys snow skiing, hiking, softball and football. His father, Lawrence M. Walheim, Jr., resides in Visalia, California. His mother, Avis L. Walheim, is deceased.
