Doors create x-y (flat) axis openings in between different room types on a spaceship.
There are three varieties of door corrisponding to the different types of hatches, with two sizes for each. Small doors take a fixed amount of space, while large doors stretch to fit whichever wall they are placed along, choosing the smaller wall for its limit.
Hull doors open to the outside of the spaceship, and are used to provide access to boarding crew in the absence of a transporter. They may be locked and closed at both the Captain's Chair and the Helm (see Controls). Large hull doors may be opened at both as well, and Space Fighters may open them to Vehicle Bays.
Crew doors are doors that may be locked to passengers at the Captain's Chair and the Helm. They otherwise behave as ordinary doors.