Section 3.6 - Assembly and Construction
Assembly refers to putting together parts or component systems to make a functional complete device. Construction refers to permanent installations not intended to move often or ever and consisting of many devices and systems. These tasks typically consist of many simple steps in series.
Assembly methods can be organized by the type of operator and the type of connections are made between elements
Assembly methods can be categorized by the type of operator that performs the assembly:
- Manual Assembly - This is performed by humans using manual dexterity and strength. It can be assisted by tools and fixtures for leverage, speed, and positioning.
- Robotic Assembly - This is performed by robots either under human remote control or computer control.
- Automatic Assembly - This is where the devices to perform the assembly task are built into the components.
Construction can be organized by analogy to Earth construction, with suitable modifications
Delivering construction equipment and supplies to the construction site from other locations.
When launching multiple components from Earth that need to be collected in one place for assembly, if the orbits are similar, then a single vehicle dedicated to the job is more efficient than including a propulsion and navigation system on each component payload . We call that vehicle an Orbital Tug. Besides propulsion, navigation, and means to grab the payloads, it needs the ability to periodically refuel. This can be done with occasional payloads being fuel tanks, which the Tug attaches to itself as needed. In order not to be left stranded, it should have at least two tank locations, and install a fresh tank while the second one still has some fuel left. If you have more than one Tug, they should be designed to grab each other for heavier cargos needing more total propulsion, or in case one stops working and needs to be returned for repair.
Positioning items within the construction site to the point of use.
Mechanical Docking Systems
Unpacking a component shipped in a compact state to an operating configuration.
Where you are doing construction on or near a natural body, and you need to modify the construction area by road-building, excavation, and other methods.
Cast and Block Structures
These are not pressure tight structures, but installed by methods like casting concrete or stacking blocks
These are from metal, wood, plastic, or other materials delivered as components to be assembled on site
Outfitting involves installing and activating items within a larger construction element once it is in place.
Sealing and Protection
- Gralla and De Weck Strategies for On-Orbit Assembly of Modular Spacecraft, JBIS, vol 60, p 219, 2007.