This number "1" patch signified that the wearer was chief of the Space Shuttle launch pad closeout crew, the small team who assisted the astronauts in boarding the vehicle and closed the hatch for launch. Each member's number was displayed on each side of the uniform for easy recognition on duty and in photographs.
The closeout crew chief for the last ten years of the Space Shuttle program, Travis Thompson, gave his complete uniform, including this patch, to the Museum after the final launch of the shuttle in 2011.
This object is on display in Mary Baker Engen Restoration Hangar at the Steven F. Udvar-Hazy Center in Chantilly, VA.