NASA Administrator Jim Bridenstine, left, helps place a lei at the Space Shuttle Columbia Memorial with Kristy Carroll, center, and daughter Vivian Carroll, who were friends of Space Shuttle Columbia pilot William McCool, during NASA's Day of Remembrance, Thursday, Feb. 7, 2019, at Arlington National Cemetery in Arlington, Va. Wreaths were laid in memory of those men and women who lost their lives in the quest for space exploration. Photo Credit: (NASA/Aubrey Gemignani)