This "landing guest" button from the NASA Kennedy Space Center admitted its wearer to the landing of STS-106, a flight of the Space Shuttle orbiter Atlantis, which had docked with the International Space Station.
Having different colors on the buttons, in this case green, allowed NASA officials to know that buttons were not being reused.
A landing guest button served multiple purposes. Wearing it identified the bearer as authorized to be present in certain viewing areas on the premises at NASA. After the landing, the button became a souvenir.
Valerie Neal donated the button to the Museum in 2012.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.