Col. Christopher Thompson (left), 89th Airlift Wing vice commander, salutes President Barack Obama and first lady, Michelle Obama, as they ascend the stairs to Air Force One at Joint Base Andrews, Md., Jan. 10, 2017. The president’s next scheduled flight on Air Force One is Jan. 20, Inauguration Day, when his successor, president-elect Donald Trump, takes the oath of office. (U.S. Air Force photo by Staff Sgt. Joe Yanik)