Space Construction

Large structures in space, such as modular space stations, global communication and information services platforms, and satellite power systems (SPSs), will all require on-orbit assembly operations by space construction workers. Space construction requires protection of the workforce and some materials from the hard vacuum, intense sunlight, and natural radiation environment encountered above Earth’s protective atmosphere.

Outer space, however, is also an environment that in many ways is ideal for the construction process. First, because of the absence of significant gravitational force (i.e., he microgravity experienced by the free-fall condition of orbiting objects), the structural loads are quite small, even minute. Structural members may therefore be much lighter than terrestrial structures of the same span and stiffness. Second, the absence of gravitational forces greatly facilitates the movement of material and equipment. On Earth the movement of materials during a construction operation absorbs a large portion of the total work effort expended by construction personnel and their machines. Third, the absence of an atmosphere with its accompanying wind loads, inclement weather , and unpredictable changes permits space work to be planned accurately and executed readily without environmental interruptions (except perhaps due to solar flares, which would increase the radiation hazard).

Automated fabrication is considered to be a key requirement for viable space construction activities. Work in space will require the close interaction of astronauts and very smart machines. For example, the advanced maneuverable spacesuit will be a versatile, self-contained, life-supporting backpack with gaseous-nitrogen-propelled jet thrusters that will enable a space worker to travel back and forth to various space construction locations. The automated beam builder will be a machine designed for fabricating “building-block” structural beams in space. Combined with a space structure fabrication system, the beam builder could allow space workers to manufacture and assemble structures in low Earth orbit (LEO) using the International Space Station (ISS) as an early “construction camp.” Eventually, as the demand for more sophisticated space construction and assembly efforts grows, permanent space construction bases could be established in LEO and elsewhere in cislunar space.

Remote astronaut workstations could be mounted on large manipulator arms attached to the space station or space base. These would have a convenient tool and parts bin, a swing-away control and display panel, and lights for general and point illumination. The closed version of this would involve a pressurized human-occupied remote workstation (space construction module) that contains life support equipment and controls and displays for operating dexterous manipulators. The 20^th century has already distinguished itself with significant achievements in space exploration; now, it is up to us to make use of the pros of space construction and set another benchmark. 

Questions to Ponder

• What are the advantages offered by Space Construction?
• What are the challenges posed by Space Construction?