Astronauts Vande Hei and Acaba at the Arlington National Cemeter

NASA astronaut Joe Acaba, left, and Mark Vande Hei, right, watch as Julie Vande Hei, wife of Mark, takes a moment after placing a flower at the gravesite of former astronaut and U.S. Senator John Glenn, Friday, June 15, 2018 at the Arlington National Cemetery in Arlington, Va. Photo Credit: (NASA/Aubrey Gemignani)