One of the biggest problems with outer space is getting there. Launching a fully automated, compact payload into geosynchronous orbit with disposable rockets can cost anywhere from $10,000 to $13,000 per pound or payload. That may sound feasible, but these prices increase tremendously when a human presence is required.
When the space shuttle program was in operation, a typical launch would cost approximately $450 million. The shuttles had a maximum payload of 55,250 pounds, so a fully loaded shuttle took materials to orbit for roughly $8,000 per pound. This, again, is a bearable cost if only the weight of the part was considered, but a per launch cost of $450 million is prohibitive by any standards.
The International Space Station is constructed with triply redundant systems, and spare parts are maintained whenever possible. If a part fails in space and no replacement is immediately available, then the only option currently available is a long wait and an expensive slog back up the gravity well.
To minimize costs, cargo transported to space must be as compact and as lightweight as possible. Transit from Earth to space, however, is a punishing journey. To survive the trip, materials must have certain minimum strengths. The stresses on materials once they are in space are far less than the stresses experienced when travelling into space. Once in orbit they can be extremely lightweight and gossamer-thin.
A newly formed start-up company, Made In Space, is proposing an alternative to traditional manufacturing of these components. Made In Space proposes to construct essential components for the International Space Station, or for any other inhabited structure that might someday exist on the Moon or Mars, using on-site additive manufacturing techniques. The technology of additive manufacturing, which is commonly described as 3D printing, has grown tremendously in recent years, and Made In Space believes that it is time to start leveraging this technology to create similar advancements in the aerospace industry.
3D printing offers multiple advantages over the current method of supplying replacement parts. First, the logistics of resupply would be change dramatically. Supply shipments would consist of uniform volumes of raw materials and not delicate or irregularly shaped parts. Second, utilization of storage space on an orbiting space station, or any other structure, would be used more efficiently for the same reasons. Components would be printed as needed, and storage would be limited to efficiently packaged raw materials. New or updated components could be transmitted to distant locations as data files for the 3D printer. This would allow space stations to remain modern.
As the International Space Station is currently designed, many critical components could be constructed by 3D printing. As the technology matures and additional possibilities are added to the existing portfolio of raw materials, the design of future space shelters or transport vehicles will undoubtedly become optimized for components manufactured in this fashion. It is not inconceivable that a future colony on the Moon or Mars could be constructed from parts manufactured entirely on-site by 3D printing.
Larger and more complex 3D printers could be used to produce larger structural components, or the design of the structural components could be redirected to more modular approaches. The different stress and load requirements of space open entirely new realms of possibilities.
Of course, transporting a 3D printer and material stock to orbit or the surface of the Moon is an expensive venture in itself, but the use of 3D printing on Earth may also result in reduced component costs and a complete redesign of the way orbital entry vehicles are now envisioned.
3D Printing to Infinity and Beyond!
by Mark Fleming