Modular Lunar Station

Publisher's blurb: "As humanity reaches for the stars an increasing number of governments, corporations and private enterprises have begun to settle moons and planets. The Modular Lunar or Planetary Station or MLPS is your cost-effective solution to creating a wide range of custom-built bases for hostile environments. The MLPS is a modular system that offers a great deal of flexibility and which can be deployed in a range of otherwise hostile environments. Simply select the modules you require for the installation you wish to construct. Each module is self-contained, pressure doors in the external hull can only be opened when the relative pressure on each side is equal, and an expandable collar around each pressure door allows you to connect modules to one another, creating short corridors between modules."