franchise-star-trek-tng-technical-manual1

3.1 MAIN BRIDGE3.1.3 Main Bridge\from an interlaced microfoamduranium filament shell gammaweldedto a tritanium truss structural framework. The innerenvironmental envelope is fabricated from low-density expandedceramic-polymercomposite segments, providing bothatmospheric integrity and thermal insulation.During the initial spaceworthiness tests of the originalUSS Galaxy prototype vessel, the standard Galaxy classbridge module was not yet fully operational. Instead, acustom-built module was used that was equipped with independentlife-support and sublight propulsion capabilities. Thisunit was used as a self-contained crew compartment duringthe initial shakedown and could have been ejected, carryingthe crew to safety in the event of a catastrophic failure of thespaceframe or propulsion system.It is anticipated that the current bridge configuration of theGalaxy class starship will remain relatively unchanged for anumber of years. Current planning calls for annual designreviews of the bridge and control systems, with major systemreplacements projected at twenty-year intervals.The concept of the replaceable bridge module originated during Star Trek V, when we were working with Herman Zimmermanon a new Enterprise bridge that was quite a bit different from the one seen in Star Trek IV. We rationalized that this was becausethe bridge, located at the top of the saucer, was a plug-in module designed for easy replacement. This would permit the ship'scontrol systems to be upgraded, thereby extending the useful lifetime of a starship, and would make it easier to customize aparticular ship for a specific type of mission. This concept also fits the fact that we've seen the main bridges of at least fourdifferent Miranda class starships, the Reliant (Star Trek II), the Saratoga (Star Trek IV), the Lantree ("Unnatural Selection"),and the Brattain ("Night Terrors"), each of which had a different bridge module.