Space manufacturing
[5] In-space manufacturing removes spacecraft design limitations due to launch parameters (mass, vibration, structural load, etc.)
The space environment, in particular the effects of microgravity and vacuum, enable the research of and production of goods that could otherwise not be manufactured on Earth.
In-space manufacturing supports long-duration space missions and colonization by enabling on-site repair and infrastructure development beyond Earth.
Additionally, in the area of spaceflight technology, space manufacturing enhances mission safety by decentralizing manufacturing activities and establishing redundancy in critical systems, allows for customized production tailored to specific mission requirements, fostering rapid iteration and adaptation of designs, drives technological innovation in materials science, robotics, and additive manufacturing, with applications extending beyond space exploration, and lays the foundation for space-based infrastructure development, supporting a wide range of commercial activities and scientific research.
The station was equipped with a materials processing facility that included a multi-purpose electric furnace, a crystal growth chamber, and an electron beam gun.
Among the experiments to be performed was research on molten metal processing; photographing the behavior of ignited materials in zero-gravity; crystal growth; processing of immiscible alloys; brazing of stainless steel tubes, electron beam welding, and the formation of spheres from molten metal.
NASA and Tethers Unlimited will test the Refabricator aboard the ISS, which is intended to recycle plastic for use in space additive manufacturing.
It may also prove possible to extract hydrogen in the form of water ice or hydrated minerals from cold traps on the poles of the Moon.
In the near term, relatively straightforward methods can be used to extract aluminum, iron, oxygen, and silicon from lunar and asteroidal sources.
Less concentrated elements will likely require more advanced processing facilities, which may have to wait until a space manufacturing infrastructure is fully developed.
[clarification needed][9] So a readily available source of useful volatiles is a positive factor in the development of space manufacturing.
Thus an automated ship can scrape up loose surface materials from, say, the relatively nearby 4660 Nereus (in delta-v terms), process the ore using solar heating and CO, and eventually return with a load of almost pure metal.
If the plant is built in orbit around the Earth, or near a crewed space habitat, however, telerobotic devices can be used for certain tasks that require human intelligence and flexibility.
Bulk soil from the Moon or asteroids has a very low water content, and when melted to form glassy materials is very durable.
The methods being investigated include coatings that can be sprayed on surfaces in space using a combination of heat and kinetic energy, and electron beam free form fabrication[12] of parts.
With 3D printing technologies, rather than exporting tools and equipment from Earth into space, astronauts have the option to manufacture needed items directly.
[15] The Refabricator experiment, under development by Firmamentum, a division of Tethers Unlimited, Inc. under a NASA Phase III Small Business Innovation Research contract, combines a recycling system and a 3D printer to perform demonstration of closed-cycle in-space manufacturing on the International Space Station (ISS).
Water from lunar sources, Near Earth Asteroids or Martian moons is thought to be relatively cheap and simple to extract, and gives adequate performance for many manufacturing and material shipping purposes.
Water used in steam rockets gives a specific impulse of about 190 seconds;[citation needed] less than half that of hydrogen/oxygen, but this is adequate for delta-v's that are found between Mars and Earth.
[citation needed] These uses include various thermal and electrical insulators, such as heat shields for payloads being delivered to the Earth's surface.
Metals can be used to assemble a variety of useful products, including sealed containers (such as tanks and pipes), mirrors for focusing sunlight, and thermal radiators.
As the structure does not need to support the loads that would be experienced on Earth, huge arrays can be assembled out of proportionately smaller amounts of material.
The generated energy can then be used to power manufacturing facilities, habitats, spacecraft, lunar bases, and even beamed down to collectors on the Earth with microwaves.
These future projects might potentially assemble space elevators, massive solar array farms, very high capacity spacecraft, and rotating habitats capable of sustaining populations of tens of thousands of people in Earth-like conditions.
Once this barrier is significantly reduced in cost per kilogram, the entry price for space manufacturing can make it much more attractive to entrepreneurs.
After the heavy capitalization costs of assembling the mining and manufacturing facilities are paid, the production will need to be economically profitable in order to become self-sustaining and beneficial to society.
The economic requirements of space manufacturing imply a need to collect the requisite raw materials at a minimum energy cost.
The cost of space transport is directly related to the delta-v, or change in velocity required to move from the mining sites to the manufacturing plants.
