The Shuttle Sign, Space Shuttle Cutout, or "Shuttout" is a painted, wooden cutout of a Space Shuttle orbiter, approximately two meters in length. If matching cutouts of the Shuttle's solid rocket boosters or an external tank ever existed, their whereabouts are no longer known. It is made out of plywood, and is typically stored on the roof of the habitat, roughly above the rear bunks of the longhouse. Its origins are unknown, as is its relationship to Galileo. Unlike other plywood and chipboard objects relegated to the roof of the habitat, it is typically not used as a walkway.