This baseball-style cap was part of the uniform worn by members of the Space Shuttle launch pad closeout crew. These men and women made a final check of the astronauts' launch-entry suits before boarding, assisted the Shuttle crew into their seats, buckled them in, and closed the orbiter hatch. The closeout crew worked for United Space Alliance, a NASA contractor. The donor of this cap, Travis Thompson, joined the closeout crew in 1983, served in that role for almost 100 missions, and was chief for the last ten years of Shuttle missions.
Travis Thompson gave his complete uniform to the Museum after the final Shuttle launch in 2011.