Before joining Boeing in 1996, O'Donoghue was a NASA research pilot who worked on a variety of aeronautical research and space science programs. He initially resisted Boeing's interest in recruiting him to be a test pilot for the Joint Strike Fighter program. But less than a month later, he was the lead test pilot of the X-32B Short Take Off and Vertical Landing Concept Demonstrator Aircraft. Dennis left Boeing to become Chief of Flight Operations for Eclipse Aviation.