Pilot of the STS-116 mission and one of the first astronauts to be dismissed from NASA.
He earned a Master's degree in Aviation Systems from the University of Tennessee Space Institute.
He had a two-year affair with fellow astronaut Lisa Nowak, who in 2007 attempted to kidnap his then girlfriend Colleen Shipman.
He married Colleen Shipman in 2010, after having two children with his first wife Michaella Davis.
He and Lisa Nowak were the first astronauts to be dismissed from NASA.