Frank Lee Culbertson Jr. (born on May 15, 1949) is a former NASA astronaut and a retired captain in the United States Navy. He served as the commander of the International Space Station for almost four months in 2001 and was the only American not on Earth when the 9/11 attacks occurred. He is currently a Senior Vice President responsible for human spaceflight programmes at Orbital Sciences, including commercial transportation to the ISS.