This hatch entry tool is a metal cylinder with a 5/8 inch square drive. The round knob at the left releases the square drive so the tool can be used in a T-shaped configuration shown here.
The tool was maintained by the Dover AFB Fire Department during the years of NASA’s space shuttle program. Because Dover AFB was designated as a site where the space shuttle could land in case of an emergency landing after a launch, the base fire department or other rescue personnel could use the hatch entry tool as a way to rescue the shuttle crew. The tool was designed to break the tile covering the hatch and then open the hatch enabling entry into the shuttle.