Wreath stands at the memorial for the Challenger Space Shuttle at Arlington National Cemetery in Arlington, Virginia, on January 27, 2011, to commemorate the agency's National Day of Remembrance. Tomorrow marks the 25th anniversary of the Challenger's January 28, 1986, mission when it exploded seconds after launch from Kennedy Space Center in Florida, killing all seven astronauts aboard. AFP PHOTO / Saul LOEB (Photo credit should read SAUL LOEB/AFP/Getty Images)