Emerging technology in detail: additive manufacturing in space

Additive manufacturing (AM) in space, often referred to as in-situ manufacturing, is the process of creating objects layer by layer directly in the space environment. ⁽¹⁾Sacco, E. and S. K. Moon (2019). Additive manufacturing for space: Status and promises. The International Journal of Advanced Manufacturing Technology, 105, 4123–4146. Unlike traditional manufacturing, which often involves subtracting material from a larger block, AM builds objects, by adding material only where necessary. This technology encompasses various methods such as 3D printing, which uses materials like polymers, metals and even lunar regolith to create the tools, components and structures required for space missions. AM in space is defined by its ability to utilize locally available resources (like regolith on the Moon or Mars) and by the constraints of the space environment such as microgravity and vacuum conditions. ⁽²⁾Prater, T., J. Edmunson, M. Fiske, F. Ledbetter, C. Hill, M. Meyyappan et al. (2019). NASA’s in-space manufacturing project: Update on manufacturing technologies and materials to enable more sustainable and safer exploration. In 70th International Astronautical Congress (IAC), October (No. IAC-19. D3. 2B. 5). This technology aims to support long-term space missions, by reducing dependency on Earth-supplied materials and enhancing the sustainability of space exploration.

AM in space is relevant for several reasons. Traditional space missions are constrained by the size of the launch vehicle's fairing, which limits the size and volume of equipment that can be sent to space. AM enables the creation of larger structures directly in space, bypassing these limitations​. ⁽³⁾Prater, T., J. Edmunson, M. Fiske, F. Ledbetter, C. Hill, M. Meyyappan et al. (2019). NASA’s in-space manufacturing project: Update on manufacturing technologies and materials to enable more sustainable and safer exploration. In 70th International Astronautical Congress (IAC), October (No. IAC-19. D3. 2B. 5). Transporting materials and parts from Earth to space is extremely costly. AM can significantly reduce these costs, by allowing the production of necessary components on-site, thus minimizing the frequency and cost of resupply missions. For long-term missions, such as those to Mars, the ability to manufacture tools, parts and even habitats on-site is crucial. This capability reduces the need to carry extensive spare parts and allows for more flexible and extended missions​. ⁽⁴⁾Zocca, A., J. Wilbig, A. Waske, J. Günster, M. P. Widjaja, C. Neumann et al. (2022). Challenges in the technology development for additive manufacturing in space. Chinese Journal of Mechanical Engineering: Additive Manufacturing Frontiers, 1(1), 100018. Moreover, the ability to produce large structures like solar arrays, antennas and habitat modules in space opens up new possibilities for mission designs that were previously impractical or impossible due to size and weight constraints. ⁽⁵⁾Makaya, A., L. Pambaguian, T. Ghidini, T. Rohr, U. Lafont and A. Meurisse (2023). Towards out of earth manufacturing: Overview of the ESA materials and processes activities on manufacturing in space. CEAS Space Journal, 15(1), 69–75.

Several types of AM techniques are being developed and utilized in space. Polymer additive manufacturing involves the use of polymers to create tools and parts. For instance, the POP3D system developed by the Italian Space Agency and ESA's manufacturing of experimental layer technology (MELT) printer can produce parts using high-strength thermoplastics like PEEK (polyether ether ketone). ⁽⁶⁾Makaya, A., L. Pambaguian, T. Ghidini, T. Rohr, U. Lafont and A. Meurisse (2023). Towards out of earth manufacturing: Overview of the ESA materials and processes activities on manufacturing in space. CEAS Space Journal, 15(1), 69–75.​ AM technologies are also being developed to enable metal printing in space such as wire-based direct energy deposition methods. This technique allows for the creation of the strong and durable components necessary for various space applications. Another method is regolith-based manufacturing, which uses lunar or Martian regolith to create structures. Techniques include binder jetting and sintering using solar energy. For example, ESA has demonstrated the use of regolith simulant with magnesium chloride binders and solar sintering to create structural elements.​ ⁽⁷⁾Wang, Y., L. Hao, Y. Li, Q. Sun, M. Sun, Y. Huang et al. (2022). In-situ utilization of regolith resource and future exploration of additive manufacturing for lunar/Martian habitats: A review. Applied Clay Science, 229, 106673. Bioprinting in space involves creating living tissue and possibly organs. ESA has explored bioprinting using bio-inks that could include human blood plasma and other readily available substances in a space mission scenario. ⁽⁸⁾ESA (2019). Upside-down 3D-printed skin and bone, for humans to Mars. European Space Agency. Available at: www.esa.int/Enabling_Support/Space_Engineering_Technology/Upside-down_3D-printed_skin_and_bone_for_humans_to_Mars.

The benefits of AM in space are manifold. AM allows for the production of parts and tools as needed, reducing the need for carrying a large inventory of spares.​ ⁽⁹⁾Makaya, A., L. Pambaguian, T. Ghidini, T. Rohr, U. Lafont and A. Meurisse (2023). Towards out of earth manufacturing: Overview of the ESA materials and processes activities on manufacturing in space. CEAS Space Journal, 15(1), 69–75. By manufacturing items in space, the overall mass that needs to be launched from Earth is reduced, leading to cost savings. AM enables the creation of complex geometries that would be difficult or impossible to achieve with traditional manufacturing methods. Using local resources like regolith for manufacturing reduces dependency on Earth, supporting more sustainable exploration missions​. ⁽¹⁰⁾Isachenkov, M., S. Chugunov, I. Akhatov and I. Shishkovsky (2021). Regolith-based additive manufacturing for sustainable development of lunar infrastructure: An overview. Acta Astronautica, 180, 650–678.​ Larger and more complex structures can be built in space, improving the performance and capabilities of spacecraft and habitats​​.

Despite its potential, AM in space faces several limitations and challenges. Assuring that materials printed in space have the same properties and performance as those manufactured on Earth is a significant challenge, especially under the harsh conditions of space that include extreme temperatures and radiation​. ⁽¹¹⁾Makaya, A., L. Pambaguian, T. Ghidini, T. Rohr, U. Lafont and A. Meurisse (2023). Towards out of earth manufacturing: Overview of the ESA materials and processes activities on manufacturing in space. CEAS Space Journal, 15(1), 69–75. Space presents unique environmental challenges, including microgravity and vacuum conditions. These factors can affect the printing process and the quality of the produced parts​. For regolith-based manufacturing, the quality and composition of lunar or Martian soil must be suitable for construction. Processes also need to be developed to efficiently extract and utilize these materials. ⁽¹²⁾​Farries, K. W., P. Visintin, S. T. Smith and P. van Eyk (2021). Sintered or melted regolith for lunar construction: State-of-the-art review and future research directions. Construction and Building Materials, 296, 123627. Many AM technologies are still at the developmental stage and require further testing and validation in order to assure they are reliable and safe enough for use in space missions. New manufacturing technologies must be integrated with existing spacecraft systems and operations, which can be complex and require significant modifications to current designs and processes.

Additive manufacturing in space: scientific publications

The scientific community has shown increasing interest in AM in space, as evidenced by the growing number of publications on the topic.

Figure D52 depicts the number of scientific documents published annually in the field of AM in space from 2014 to 2024. Several notable trends can be identified. Initially, this field experienced a slow growth rate from 2014 to 2015 indicating the nascent stages of research and foundational studies during this time. The number of publications began to rise significantly around 2016–2017, reflecting an increase in interest and early development efforts. This period likely marks the transition from exploratory research to more focused studies and early applications.

A notable dip appears in 2020, followed by a sharp increase. This surge suggests a period of accelerated research and significant advancements, possibly driven by technological breakthroughs, increased funding and heightened interest from both academia and industry. The subsequent years show a high level of activity, with another peak in 2023. Although has been a slight decline in 2024, the number of publications remains relatively high compared to the early years, indicating sustained interest and ongoing research efforts in the field.

Figure D53 showing origin countries for scientific publications provides insights into the geographical distribution of research activity and highlights the leading contributors globally. The United States stands out as the dominant country in the field, with the highest number of publications. This dominance reflects significant investment in space technologies and a strong research infrastructure supporting advancements in AM. Germany follows, with substantial contributions indicating robust academic and industrial research capabilities in the country.

China is also a major player, with a considerable number of publications. This highlights China's growing focus on space exploration and advanced manufacturing technologies, driven by national initiatives and substantial funding. The Kingdom of the Netherlands and France have notable numbers of publications, signifying active research communities and potential collaborative projects within Europe.

Other countries, including the United Kingdom, Italy, Australia, the Republic of Korea and Finland, also contribute to the field, though to a lesser extent. This diverse but concentrated research effort underscores the global interest and collaborative nature of advancements in AM in space.

Additive manufacturing in space: patent data

The examination of the patent landscape reveals that patenting activity in the field of AM in space has picked up speed over the last years. The number of published patent families has increased from only 10 in 2014 to 46 in 2023 (Figure D54).

The United States leads the country ranking for AM in space research, with 141 patent families published since 2000 (Figure D55). China, Germany, France and the United Kingdom are other important research locations.

Additive manufacturing in space: patent examples

In 2019 BAE Systems developed early AM systems in space. The invention (EP3527373A1) pertains to an advanced system for manufacturing articles in space, integrated into a space-based object such as a space vehicle or station. The core component is an AM apparatus that uses supplied feedstock to produce various articles. This apparatus is supported by a feedstock storage module, ensuring a steady material supply, and a controller that manages the manufacturing operations.

A key feature is the recycling module, which converts waste material into usable feedstock, enhancing sustainability and efficiency, by minimizing waste and reducing the need for new materials. Additionally, the system includes a machining apparatus for further processing, with waste from both AM and machining being recycled.

Source: EP3527373A1.

The space-based object can dock with other objects, allowing the exchange of waste materials and manufactured or repaired articles, facilitating resource sharing in space missions. A storage module holds articles for repair, which the manufacturing apparatus can process, thus extending the life of critical components.

An inspection module assures the quality of manufactured articles, and the system can communicate with an Earth-based facility for data transfer and remote control. The manufacturing apparatus is versatile, capable of using wire, plastic or metal feedstock, making it adaptable for a variety of needs. Designed to be autonomous or remotely controlled, this system represents a significant advancement in in-space manufacturing, supporting long-term missions with improved efficiency and sustainability.

While the BAE invention focuses on focuses on sustainable manufacturing with integrated recycling, a patent from Made in Space Inc. (EP16857937A) put an emphasis on advanced assembly and integration capabilities in a space environment.

The invention pertains to a system and methods for in-space manufacturing and assembly of spacecraft devices and techniques. This system is designed to produce objects in a space environment, incorporating several innovative components to assure efficient and effective manufacturing processes.

At its core, the system includes a build device equipped with a build area and a material bonding component. This component receives portions of the material used to fabricate the object. Within the build area, at least one gripper contacts the object to provide support and serve as a heat sink, cooler or electrical dissipation path for the object. The build device also features a movement mechanism that positions the device relative to the object during production.

Source: EP16857937A.

An additional feature of the system is its ability to operate within an infinite build area on at least one manufacturing axis, allowing the construction of objects larger than the build device itself. The system also integrates a knitted component for creating a web applied to the object during manufacturing, thus enhancing structural integrity.

The system's versatility is further demonstrated by its inclusion of an antenna element release mechanism, which allows for the extrusion and integration of antenna elements into the object. This capability ensures the seamless assembly of complex spacecraft components. To enhance functionality, the system comprises a robot arm designed to reach and manipulate distal portions of the object, a z-traverse system incorporating the gripper, and a buffer mechanism to manage the effects of gravity center movement in microgravity environments. The build device can either remain attached to the completed object, providing functional elements, or detach once the object is finished.

Additionally, the system supports the construction of spacecraft components and structures using AM materials by an extended structural additive manufacturing machine (ESAMM) device. This ESAMM device also facilitates the inspection, assembly and integration of electronic components and assembly accessories to form a complete spacecraft system.

The method associated with this system involves using the space or microgravity environment to construct spacecraft components, dissipate heat, conduct electricity and assure the structural integrity of the object during and after manufacturing. The process includes inspecting the components during construction, installing solar panels, forming antennas and repeating those steps to build multiple systems of the spacecraft. Overall, this invention represents a significant advancement in in-space manufacturing, offering comprehensive solutions for producing, assembling and integrating complex spacecraft components directly in the space environment.