Project OSIP

Among the several criticalities for future space exploration and colonization is undoubtedly the supply of raw materials to manufacture every component needed. The utilization of in situ resources present on the surface of a moon/planet, as well as secondary raw materials extracted from end-of-life components, represents the only sustainable solution for long-term out-of-Earth permanence.

Moreover, Additive Manufacturing (AM, commonly known as 3D printing) is a new paradigm of manufacturing with unrivalled freedom of geometry and equipment flexibility, which is ideal for low-volume production and customizability required from the Lunar exploration. Indeed, 3D-printing equipment can manufacture any geometry without the need for molds or fixtures specific for a single part, and therefore it is especially suitable not only for in space manufacturing but also on Earth applications with low production volumes, complex and optimized geometries, and custom high-performance materials. Among the 3D printing technologies, Fused Filament Fabrication (FFF) is a material extrusion-based technique which has been proven to be employable in reduced or zero gravity, and therefore represents the most promising way to additively manufacture component in the space environment. Moreover, Fused Filament Fabrication presents low equipment cost, low material waste and general ease of processing compared to other Additive Manufacturing technologies, and it is thus favorably applied in a variety of on-earth applications.

Magnetic materials, both with soft and hard magnetic behavior, are key components in many devices aboard any spacecraft, such as motors, mechanisms, actuators and sensors. The most common route for the manufacturing of magnets is the sintering process, which produces the highest magnetic performance possible but it is energy intensive and requires molds for each geometry. The alternative is the use of bonded magnets, which are composite materials composed of a polymeric matrix with a high content of magnetic filler. Being polymer-based, bonded magnets can benefit from all the manufacturing processes typical of polymers, such as extrusion, injection molding or filament based 3D printing. Therefore, the possibility of manufacturing magnetic components with an Additive Manufacturing process and with materials available in situ is a valuable perspective for the future of space agencies.

Therefore, the aim of this project was to develop innovative composite and nanocomposite materials with soft magnetic fillers processable via Fused Filament Fabrication 3D printing to manufacture brushless motor components for space applications. With the developed materials, a brushless direct current motor was designed via Finite Element analysis to optimize the static, dynamic and electromagnetic performances arising from the mechanical and electromagnetic properties of the 3D printed soft magnets. Finally, a prototype of a motor stator with the optimized design and best performing material was 3D printed as a proof of concept of the application on the innovative composite for low power motors in space environment.