WASHINGTON (NRC PR) – Additive manufacturing, also known as 3-D printing, could contribute positively to space missions, for example by enabling in-orbit manufacture of replacement parts and reducing launch logistical requirements, but the specific benefits and potential scope of the technology’s use remain undetermined, says a new report from the National Research Council. The report illustrates the substantial gaps between the vision for additive manufacturing in space and the limitations of the technology, as well as outlines the progress that has to be made to develop it for such use.
“Many of the claims made in the popular press about this technology have been exaggerated.” said Robert Latiff, chair of the committee that wrote the report, president of Latiff Associates, and a former Air Force Major General. “For in-space use, the technology may provide new capabilities, but it will serve as one more tool in the toolbox, not a magic solution to tough space operations and manufacturing problems. However, right now NASA and the Air Force have a tremendous resource in the form of the International Space Station,” Latiff added. “Perfecting this technology in space will require human interaction, and the Space Station already provides the infrastructure and the skilled personnel who can enable that to happen.”
Additive manufacturing is the process of joining materials — usually layer upon layer — to make objects from 3-D model data. The addition of material one layer at a time, placed in very specific regions, significantly reduces the amount of waste created during production. Additive manufacturing offers unique economic incentives for space operations by cutting raw material costs, reducing payload sizes, and eliminating the need to frequently launch spare or replacement parts into orbit. Although additive manufacturing is a fairly mature technology for components that can be manufactured on the ground, its application in space is not feasible today, except for very limited and experimental purposes, the report says.
The committee found that multiple limitations preclude fully automated additive manufacturing in space from becoming an immediate reality. The vacuum of space, zero gravity, and intense thermal fluctuations all pose extreme and harsh environmental obstacles. These factors are important not only in terms of completing the manufacturing process but also in how they can alter the integrity of the final product.
Furthermore, a number of impacts and obstacles need to be considered in the cost-benefit equation for additive manufacturing. The largest disadvantages stem from the high costs of equipment operation, maintenance, and infrastructure platforms such as a reliable power source that does not detract from spacecraft operations. Automation presents another unknown cost, because while it is often cheaper and more efficient to have human labor complete basic tasks, such as moving parts from one machine to the next, human labor in space is very expensive. At a minimum, further investments in human telepresence and robotics will be required, the report says.
The committee warned, however, that actual production costs should not be the sole criterion for evaluating the benefits of in-space additive manufacturing, but consideration should be given to the value of creating structures and functionalities not feasible without the technology. For instance, additive manufacturing might enable the construction of large structures in space, structures too big or fragile to be launched on top of a rocket.
In-space manufacturing is likely to have a more significant impact on human space missions than for robotic spaceflight, the report concludes. However, additive manufacturing could greatly benefit from well thought out technology roadmaps, standards of quality and performance, common terminology, and other professional engineering standards.
Because NASA is currently the leader in development of space-based additive manufacturing technology and also operates a valuable research platform, the International Space Station, the committee recommended that the agency sponsor a space-based 3-D printing workshop to bring together experts in the field, and take other actions to improve communication inside and outside of the agency. NASA should also develop an agency-wide roadmap for developing the technology. Because perfecting and exploiting the technology will require input from multiple disciplines, strong communication is vital. Due to time constraints, NASA should also quickly identify any experiments that it can develop and test aboard the International Space Station during its remaining 10 years of service.
The committee believes that in-space additive manufacturing is an area where cooperation between civil agencies and the military can and should occur. The Air Force should establish a roadmap with short- and longer-term goals for evaluating the possible advantages of additive manufacturing in space. The Air Force and NASA should also consider additional investments in the education and training of both materials scientists with specific expertise in additive manufacturing and spacecraft designers and engineers with deep knowledge of the use and development of 3-D printing systems. Finally, the Air Force should make every effort to cooperate with NASA on in-space additive manufacturing technology development including, but not limited to, conducting research on the International Space Station, jointly sharing the costs of research, and sharing data.
The study was sponsored by NASA and the U.S. Air Force. The National Academy of Sciences, National Academy of Engineering, Institute of Medicine, and National Research Council make up the National Academies. They are private, independent nonprofit institutions that provide science, technology, and health policy advice under a congressional charter granted to NAS in 1863. The National Research Council is the principal operating arm of the National Academy of Sciences and the National Academy of Engineering. For more information, visit http://national-academies.org.