Robert Louis Behnken (; born July 28, 1970) is a NASA astronaut, engineer, and former Chief of the Astronaut Office. Behnken was selected as an astronaut by NASA in 2000 and is a veteran of two space shuttle flights. A native of Missouri, Behnken flew STS-123 in March 2008 and STS-130 in February 2010, logging more than 708 hours in space, and more than 37 hours during six spacewalks. Behnken most recently served as Joint Operations Commander on the first crewed flight of the SpaceX Crew Dragon, the Demo-2 mission, which landed August 2, 2020. He also served as Flight Engineer on the International Space Station for Expedition 63.