NASA Administrator Charles Bolden and his wife Alexis watch as Tomb guards with The Old Guard, the 3rd U.S. Infantry Regiment, perform a changing of the guard prior to a wreath-laying ceremony as part of NASA's Day of Remembrance, Wednesday, Jan. 28, 2015, at Arlington National Cemetery in Arlington, Va. The wreaths were laid in memory of those men and women who lost their lives in the quest for space exploration.