CAPE CANAVERAL, Fla. -- A flag flies at half-staff near the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in Florida during a Day of Remembrance wreath laying ceremony to honor members of the NASA family who lost their lives while furthering the cause of exploration and discovery. The large mirror made of black granite was designated as a national memorial by Congress and President George Bush in 1991. It honors 24 United States astronauts, including the crew members of space shuttles Columbia and Challenger, Apollo 1, and those who died in training and commercial airplane accidents. The memorial is a project of the Astronauts Memorial Foundation and was paid for by Florida residents who purchased special Challenger mission automobile license plates. 2011 marks the 25th anniversary of the loss of Challenger, which broke apart over the Atlantic Ocean 73 seconds into flight on Jan. 28, 1986. Photo credit: NASA/Kim Shiflett KSC-2011-1210
