March 2016 – As the first company worldwide, Tesat-Spacecom, one of the largest space technology companies in Germany, has pioneered the application of additive manufacturing techniques, also known as 3D printing, for the production of microwave components. The breakthrough took place within the framework of an activity supported by ESA through the Competitiveness & Growth Element of the ARTES programme.

Additive manufacturing has been used for many years in medical technology for producing, amongst other things, metallic implants and bone and tooth replacements. More recently, this technique has evolved to the stage where high-quality aluminium parts can be produced. In an approach known as Additive Layer Manufacturing (ALM), metallic powder is deposited layer by layer, and a high-power laser with a beam size in the order of 1/10 mm is used to weld pre-defined shapes for each layer.

Up until recently, the application of this manufacturing technique for microwave components was hindered by the roughness of the resulting surfaces, as this resulted in degraded performance. In the ARTES-supported activity, a team from TESAT and Fraunhofer ILT, with the assistance of ESA technical experts, was able to overcome this issue, paving the way to using this technique to produce, for the first time, single-piece microwave components made from aluminium, including filters, couplers, and waveguide runs.

Using this technique, very complex single-piece components can be produced in a short time, at reasonable cost and in small numbers. Almost arbitrary geometries can be produced that are not possible or only very difficult and expensive to obtain with traditional milling techniques.

ESA support for the application of ALM in the European space industry dates back to 2008. In that year, ESA's Payload Engineer Christoph Ernst, and ESA’s Material Expert Laurent Pambagian learned about the then new technique and saw that it had great potential. They organised internal funding to produce a series of microwave parts in aluminium and titanium by means of 3D printing. This success led to a series of development activities supported through the ARTES programme, in which TESAT took part.

"The results of these efforts are quite impressive,” says ESA Microwave Engineer Cesar Miquel Espana, who oversaw the activities. “We are now seeing RF performance equivalent to traditionally manufactured parts, often with reduced mass as well."

TESAT’s Dr. Siegbert Martin, Head of Passive Microwave Products:

How is the company currently using ALM techniques?

“Since 2015 ALM has become a part of our daily work. We have started using RF devices made by ALM in our test area. This generates cost savings on the one hand, on the other we learn and understand the technology more and more:”

Is it being used for production yet?

“ALM helps us to find test solution faster by special waveguide routings or dedicated filters. Further I observe an interesting transformation in application: At first we start replacing milling production, but now we change our ways of thinking and finding solutions by using the full potential of ALM.”

When will the first mission be?

“The innovation run has been kicked off and we have targeted three additional areas on satellite.

• Support structures for filter networks
• ALM is becoming an essential part of our FELXOMUX products”
• Our new developments have already considered the ALM design guidelines. Thanks this we are very keen to use this new manufacturing technology.

Roadmap for deploying ALM

“The space industry is requesting innovations and we have now a key in our hand to deliver. After further performance evaluation this year, we are targeting to supply FM units in 2017.”

“The space industry is geared towards small series production of complex parts. This is precisely what additive manufacturing is ideal for,” says ESA's Christoph Ernst. “Thanks to this important breakthrough, leading the way to a significant cycle of spacecraft RF hardware optimisation in terms of mass and performance but also to enable quick turn-around of early prototypes and reduce the delivery times.”