Former NASA Administrator Sean O'Keefe, second from right, answers a question during a panel discussion with NASA Administrator Jim Bridenstine and former NASA Administrator Charles Bolden at an event celebrating NASA's 60th anniversary at the Center for Strategic and International Studies on Monday, July 23, 2018 in Washington. Bridenstine, O'Keefe, and Bolden answered questions about the past and future of the agency. (Photo Credit: NASA/Joel Kowsky)