The Space Shuttle "Challenger" Memorial was dedicated on May 20, 1986, in memory of the crew of flight STS-51-L, who died during launch on January 28, 1986. Transcribed on the back of the stone is the text of the John Gillespie Magee, Jr. poem "High Flight", which was quoted by then President Ronald Reagan when he addressed the disaster. Although many remains were identified and returned to the families for private burial, some were not, and were laid to rest under the marker. Two crew members, Dick Scobee and Michael Smith, are buried in Arlington. On February 1, 2004, NASA Administrator Sean O'Keefe dedicated a similar memorial to those who died when the Shuttle "Columbia" broke apart during reentry on February 1, 2003. Astronauts Laurel Clark, David Brown, and Michael Anderson, who were killed in the "Columbia" disaster, are also buried in Arlington.