User:DBBell/Sandbox/Orbital construction

Orbital construction is the practice of constructing or assembling structures in outer space, specifically, within the orbit or Lagrangian point of a large body, such as a planet, moon, or star. This involves working in conditions of microgravity and hard vacuum.

Types of construction
Modular/docking - Fabrication and testing of completely functional components has been performed on the ground and assembly is completed via a docking interface or other mated adapter.

This activity encompasses most of the construction activity performed so far, including Mir and the International Space Station.

Prefabricated materials - Fabrication of building materials has been completed on the surface, however, assembly requires assembly and final testing of components on orbit. In building habitable structures, this would be comparable to the methods of constructing large buildings or ships.

Several upgrades to the Hubble Space Telescope involved complex EVAs to replace internal components, several of which were not readily designed for replacement in orbit. Since each unit was integral unto its own function and thoroughly tested prior to launch, the complexity of the activity exceeds that of the application of a modular design, but not transformed into a larger component while in orbit.

Total fabrication - Raw materials are processed using space manufacturing processes which generate the construction materials used in the assembly.

This has yet to be accomplished, however the idea would be that raw materials are launched or transferred to the construction site and processed into the materials and finished components required for construction. Sources of raw materials include asteroids, material from jovian rings, or material launched from the surface, such as employing the use of a large mass driver to propel material from the surface or utilizing a space elevator.

Fictional examples
The orbital space station depicted in 2001: A Space Odyssey and the Babylon stations from Babylon 5 are examples of construction using prefabricated materials that are delivered to the site for assembly.