3D Printing and Welding in Space

Using 3D printing in rockets, spacecraft, and engine components is nothing new. For example, hundreds of 3D printed parts are used in SpaceX and Boeing rockets.

Traditional manufacturing techniques like CNC prototyping are unable to produce the geometries needed to construct space equipment in a single part, requiring that additional components be added later. However, in direct metal laser sintering (DMLS), metal parts lay in a powder bed, which prevents any overhangs or delicate areas from deforming during the printing process, demonstrating how 3D printing can create significantly more complicated geometries than traditional methods.

Despite the fact that space is a harsh environment with few exploitable raw materials, there is a lot of dust drifting around. Using 3D printing technology, it’s possible to create solid structures out of dust and minuscule particles.

Because many of the parts required for space missions are made of aluminum, titanium, or steel, NASA is collaborating with a number of small companies to develop metal printing capabilities for the International Space Station (ISS).

Ways to establish complete in-space welding capability is being explored through a series of NASA flight experiments.

Why Do We Need to 3D-Print in Space?

To begin with, why would we want to use additive manufacturing in space? Is it simply for the sake of research and development? Additive manufacturing has a lot of potential in the aerospace industry. The ability to create 3D objects in space could be a game-changer.

It will greatly assist astronauts in their daily lives in orbit during space missions. For example, if they need a tool, or if something breaks or they need to replace a part, it can take a long time and tremendous cost to deliver what they need. However, repairs are much simpler if the astronaut can simply 3D-print a new part or a new tool.

Additive technology also has the potential to ease logistics. Satellite constructions could be built using a 3D printer in orbit.

In space, additive manufacturing can’t follow the same methods as it does on Earth. In order to use a 3D printer in zero gravity, the equipment must operate in a completely new environment. The machine must shape the part in a vacuum, which can make it difficult to establish the part on the build tray.

Also, the printing material and machine must be more durable and last for a longer duration. Whatever its purpose, a 3D-printed part must be extremely resistant to the harsh conditions of space, even if it is manufactured on Earth.

Which 3D Printing Materials Can Be Used in Space?

Is 3D-printed plastic suitable for use in space? Yes, but you won’t be able to use all types of plastic. Polylactic acid (PLA) and polyvinyl alcohol (PVA), for example, are incompatible with additive manufacturing in space due to their insufficient resistance to conditions in orbit.

The printing material has to be able to withstand both extreme low and high temperatures in order to be printed in space and used as a tool or satellite component. Made in Space, a California-based company dedicated to creating 3D printers for use in microgravity, plans to adopt a new type of plastic for their experiments with the Archinaut, a robotic manufacturing and assembly system, for use in space.

This novel material is a polyetherimide/polycarbonate (PEI/PC) polymer. It’s three times stronger than the standard plastic printed on the International Space Station’s interior.

Both polyetherimide and polycarbonate are thermoplastics that are commonly used in engineering. These are tough plastics that are simple to model, making them ideal for 3D printing to generate the precise forms that are required. Furthermore, these materials have excellent thermostability and resilience, making them ideal for use in space.

Metal 3D Printing Without Gravity

Metal is probably the first thing that comes to mind when you think of a durable 3D printing material. Metal is, without a doubt, an excellent choice. Researchers from the German Federal Institute for Materials Research and Testing and the Technical University of Clausthal are working on a powder-based manufacturing project to 3D-print metal items without gravity.

These researchers are working on a binder jetting-based 3D printer, which applies a forceful jet of air to stabilize the part instead of gravity. Novespace’s ZERO-G Airbus A310 was used to test this method. There are other variables to consider, such as keeping the powder in place. The layer application process must be carried out in a hermetic condition.

NASA and Metal 3D Printing

As mentioned earlier, NASA is collaborating with a variety of entrepreneurs to develop metal printing capabilities for the ISS.

On Earth, selective laser melting (SLM) is the preferred metal 3D printing process for aircraft. In this method, metal powder is fed from a hopper onto a construct plate. Each layer deposited is about the thickness of a human hair. The powder is then selectively melted and fused together using a laser. These systems are enormous and demand a lot of power. Furthermore, the powders are flammable, pose a respiratory hazard, and are difficult to control in microgravity.

Due to these limits, NASA has begun to consider alternatives to SLM for space application, and companies are developing ground-based prototypes of these systems while they are still in the research phase.

• Ultrasonic techniques use force and vibrations to combine adjacent layers of metal foil. This is being researched by Ultra Tech Machinery and Fabrisonic.
• Wire arc technologies use a welding process to deposit and fuse succeeding layers of metal wire. This is being explored by Made in Space.
• Bound metal deposition-type methods use metal particles packed in a polymer binder. This is being tested by Techshot.

Made in Space and the Archinaut 3D Printer

Made in Space’s Archinaut can 3D-manufacture a complete satellite while in orbit. This impressive machine consists of a 3D printer and robotic arms that assemble the structure’s components.

Archinaut is geared to large-scale manufacturing. Because gravity is no obstacle for this machine, it has the potential to produce pieces that wouldn’t be transportable from Earth.

What Is the Future of 3D Printing in Space?

NASA and other space agencies, as well as private endeavors, will continue to explore new methods and applications for 3D printing in space. Some of these fantastic projects are already a reality.

For example, the Refabricator is a printer launched into space by NASA in 2019. It can recycle its printing material over and over again, and it will make it possible to recycle both plastic and garbage in space. The Refabricator will be extremely beneficial in lowering the expenses of space travel as well as its effects on the environment.

The European Space Agency (ESA) is considering 3D-manufacturing their lunar base. The goal is to use 3D printing to construct a small city out of regolith.

Audi’s Lunar Quattro is a project that uses additive manufacturing. It’s a robotic vehicle that’ll be dispatched to the moon to take 360-degree photos.

Companies like SpaceX have already tested 3D-printed rocket engines, demonstrating the capabilities of additive manufacturing. 3D printing an engine, even for a rocket, may become increasingly frequent in the near future.

‍