An American flag flies at half staff at the Kennedy Space Center Visitor Complex during Kennedy Space Center's NASA Day of Remembrance.

An American flag flies at half staff near the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in Florida during Kennedy Space Center’s NASA Day of Remembrance.

The Day of Remembrance honors members of the NASA family who lost their lives while furthering the cause of exploration and discovery, including the astronaut crews of Apollo 1 and space shuttles Challenger and Columbia. Kennedy civil service and contractor employees, along with the general public, paid their respects throughout the day. The visitor complex provided flowers for visitors to place at the memorial. Photo credit: NASA/Kim Shiflett