Col. Mark T. Vande Hei (Ret.) is a retired U.S. Army colonel who finished his Army career as an astronaut. He earned his commission in the U.S. Army through the Reserve Officer Training Corps and is a graduate of the Army’s Airborne, Air Assault, and Ranger schools. He served as a leader of combat engineers, an assistant professor of physics at the United States Military Academy, and then as a space operations officer. In 2006, he started his work at NASA’s Johnson Space Center in Houston as a capsule communicator (capcom). In 2009, NASA selected him to become an astronaut. A veteran of two Soyuz launches to the International Space Station, Col. Vande Hei increased the record for the longest single American spaceflight to 355 days. He has spent 523 days in low Earth orbit and completed four spacewalks totaling more than 26 hours. He currently serves as the Flight Operations Directorate’s associate director for technical risk, the chair of the Multilateral Crew Operations Panel, the astronaut representative to the NASA Engineering and Safety Center, and the astronaut representative to the International Space Station Advisory Committee. Col. Vande Hei earned a bachelor’s degree in physics from Saint John’s University and a master’s degree in applied physics from Stanford University. He volunteers as an emergency medical technician for the Harris County Emergency Corps.