Johnson is not only a pilot who has flown combat missions in support of Operation Desert Storm, but also a safety expert. As astronaut representative, he was a key player during the investigation into the cause of the Columbia accident in 2003.
A year later, Johnson was designated as the Deputy Chief of the Astronaut Safety Branch, with emphasis on improving operational procedures and techniques to increase astronaut safety in space vehicles.
Johnson was pilot of STS-123 Endeavour in 2008, a mission that delivered Japan’s Kibo logistics module and Canada’s Dextre robot arm manipulator unit to the International Space Station. Johnson was also a robotic arm operator, employing both the Space Shuttle and Station arms in support of numerous tasks throughout the mission. He has logged 16 days in space.