August 26, 2024

Fraunhofer HHI explores thermal management of space components

August 26, 2024

Within the NanoBLAST project, Fraunhofer Heinrich-Hertz-Institut (HHI) has applied the procedure of reactive gas-assisted nanosecond laser processing on aluminum alloys for the first time to produce a sample electronic box for spacecrafts. The method was developed at Fraunhofer HHI. Together with Azimut Space GmbH, Fraunhofer HHI is driving the implementation of thermally highly emissive surface structures in the project. To this end, the researchers are developing a new technological process that transfers the structuring process from the academically established femtosecond laser system to a robust nanosecond laser system that can be operated economically. NanoBLAST was launched in February 2023 and will run for 24 months until February 2025. It is funded by the Federal Ministry for Economic Affairs and Climate Action with 407,000 euros.

Space-appropriate thermal regulation is one of the key factors that must be considered when developing space components such as electronic boxes, satellites or rocket nozzles. Unlike on earth, the vacuum of space means that it is not possible to transfer energy in form of heat to the environment through thermal conduction.

Together with Azimut Space GmbH, Fraunhofer HHI has functionalized various metal surfaces in past projects (BLAST-MA, BLAST-LARGE) using femtosecond laser processes so that they dissipate heat in a vacuum with high efficiency.

Structured surfaces have many advantages over conventionally used paints: Paints are more susceptible to temperature, can flake off or have limited compatibility with high radiation levels in space. Furthermore, structured surfaces save costs during launch, as the launch weight of the vehicle is reduced by eliminating the coating. Furthermore, there is no need for additional tests and certifications as the base material is not chemically altered. Lastly, the Fraunhofer HHI technology minimizes the ecological footprint as it completely eliminates the need for fine chemicals and solvents to coat the component.

In the current NanoBLAST project, the partners are working on further developing the technology so that it can be scaled up and brought to market.

To this end, the Fraunhofer HHI team is tackling two aspects. Their main focus is on the new development of the laser process. In previous projects, the research team used cost-intensive femtosecond laser systems. For the first time, NanoBLAST is now developing a process in which a comparable structure can be achieved on the metallic surfaces using nanosecond lasers under a reactive gas atmosphere. This new technical development will allow the entire surface of an electronics box to be structured in an economical timeframe and, above all, with massively reduced investment costs and therefore at competitive prices.

Simultaneously, the researchers are working on transferring the laser structuring developed at the institute from the laboratory conditions of a flat plate to a real component with curvatures, unevenness and recesses. To do this, they have to optimize the laser parameters for the required material and adapt the laser setup and the processing chamber to the dimensions and structural characteristics of the component.

With the completion of the first sample box, the NanoBLAST team has reached an important milestone. Following further tests, the researchers will transfer the new reactive gas-assisted nanosecond laser process to a standard market-sized aluminum box.