Jonathan Clark received his bachelor's degree from Texas A&M University, his medical degree from the Uniformed Services University of the Health Sciences, his master's degree in public health from the University of Alabama, Birmingham and completed residency at Bethesda Naval Hospital. He is board certified in Neurology and Aerospace Medicine. Dr. Clark served 26 years active duty with the US Navy and qualified as a Naval Flight Officer, Naval Flight Surgeon, Navy Diver, and Military Freefall parachutist. He flew combat medical evacuation missions in Operation Desert Storm with the US Marine Corps. Dr. Clark worked at NASA Johnson Space Center from 1997 to 2005, serving as Space Shuttle Crew Surgeon, Chief of Medical Operations, Neurologist, FAA Senior Aviation Medical Examiner and served on NASA's Spacecraft Survival Integrated Investigation Team. He recently became Chief Medical Officer for Excalibur Almaz USA, an orbital commercial space company. He teaches operational space medicine at Baylor College of Medicine's Center for Space Medicine and the Aerospace Medicine residency at the University of Texas Medical Branch. His interests are in neurologic effects in extreme environments and crew survival in space.