Space is fascinating, but it is also an extremely hostile environment – not only for humans, but for space technology as well. Vacuum conditions, intense radiation and even atomic oxygen can compromise the structure of materials. In space applications, labyrinth seals are designed to keep liquid lubricants in place while preventing contamination of surrounding subsystems. In a vacuum, lubricants gradually evaporate, potentially jeopardizing both the operation of equipment and the integrity of sensitive optical elements. And that is not the only challenge.

“In space, there is no atmosphere – and therefore no layers of adsorbed molecules separating surfaces from one another. When two clean metal surfaces come into contact, they effectively have no reason to ‘believe’ they are separate objects, so they may weld together. This phenomenon is known as cold welding, and it has already occurred in past missions, including Galileo. It is one of the issues we are trying to prevent. That is why lubricants remain one of the key topics addressed by space engineers,” explains Josef Pouzar from the Institute of Machine and Industrial Design, who has recently earned his doctoral degree.

It was precisely the inaccuracies in predicting lubricant evaporation that sparked his research. The topic proved compelling enough to gain support from the European Space Agency through its Co-funded Research programme within the Discovery initiative, which co-finances part of the costs of doctoral projects while also enabling continuous expert consultation. Securing this support is highly competitive, with a success rate of around seven percent. “If your proposal succeeds, ESA covers half of the project costs throughout your doctoral studies. At the same time, I had the opportunity to consult regularly with ESA specialists. My project supervisor on ESA’s side was René Seiler – someone who has worked at ESA for twenty-five years and contributed to most of the agency’s scientific missions,” says Pouzar, appreciating what he describes as a gateway into the world of space technologies.

Alongside Pouzar’s fundamental research, ESA also commissioned a consortium of companies to address a similar problem through the development of computational software for more accurate lubricant leakage prediction. “Their development is still ongoing. ESA aims to deliver one comprehensive outcome combining both projects, so we are currently discussing how my results could contribute to the development of the software,” adds Pouzar, who is looking forward to continuing his collaboration with the agency.

These are not the only plans Pouzar has for the outcomes of his research. Last year, at the International Engineering Fair in Brno, he and his colleague David Košťál presented an experiment they plan to launch into orbit next year as part of the experimental satellite BRNOsat. “We will compare conventional and our optimized seal designs directly in microgravity. At the same time, we are developing new measurement methods, because monitoring data directly in orbit is technically extremely challenging,” says Pouzar.

The research also extends beyond space applications. The principles of molecular flow and contamination in vacuum environments are highly relevant for semiconductor manufacturing and other vacuum-based technologies. According to Pouzar, the results could also find practical application through industrial collaboration. “One of the possibilities currently under preparation is to build on this research through a spin-off company focused on consulting, simulation, experimental validation and optimization of labyrinth seals for vacuum applications. At the same time, my long-term goal remains further professional development in the field of space mechanisms and continued cooperation with ESA,” Pouzar concludes.

(ivu)