The Mannheim-based subsidiary of the Japanese Kyocera Group is reaching for the stars: from 2023, zirconium tubes from Kyocera Fineceramics Solutions GmbH will be used to expand the electromagnetic levitator (EML) on the International Space Station (ISS). The ceramic products help with oxygen measurement and are therefore part of a new research facility that is constantly being expanded.
The levitator is a 360 kg system in the materials science laboratory in the Columbus module and was brought to the ISS in 2014 by the ATV-5 (automated transfer vehicle) "Georges Lemaître", an unmanned supply spacecraft. There, the system was installed and put into operation by Alexander Gerst. He also supervised the sample processing. The European Space Agency's funding program1 is planning to expand the EML to include a device for oxygen measurement and regulation (EML OCS - EML Oxygen Sensing and Control System), which is expected to go into operation in 2023. This will enable additional measurements under a specifically adjustable oxygen atmosphere.
Kyocera supplies essential material for oxygen measurement
Heated Sample Droplet in Electromagnetic Levitator - Photo: DLRTheadditional extension of the system with the possibility of oxygen control (OCS) will include metallized and soldered ceramic tubes made of DEGUSSIT FZY from Kyocera Fineceramics Solutions GmbH. DEGUSSIT FZY is a special material that enables precise oxygen measurement at high temperatures due to its ionic conductivity. This ionic conductivity can only be achieved by specifically adjusting the composition and the ceramic microstructure. Extensive tests of the assemblies were carried out in advance to ensure usability and reliability under the extreme conditions of a rocket launch and weightlessness.
Zirconium oxide doped with yttrium oxide (Y203) has a conductivity for oxygen ions at temperatures above 600°C. Solid electrolyte sensors with DEGUSSIT ceramics utilize this property. The zirconium oxide ceramic serves as a gas-tight separating layer between two gases with different oxygen concentrations. Equipped with electron conductors on both sides - such as a platinum layer - oxygen ions pass through the ceramic and create an electrical potential. This measures the electrical voltage and enables the oxygen content of the sample gas to be calculated. This depends on the difference in the oxygen concentration of the two gases. Air is often used as the reference gas.
The EML in use
The EML uses electromagnetic fields to position metal and semiconductor samples in a free-floating position. It also allows the materials to be melted and various material data to be recorded at different temperatures. The process takes place in a vacuum or inert gas atmosphere. Without the contact to a crucible wall, which would lead to a metrological influence due to the contact between the sample and the crucible, or the influence of gravity, which causes convection and segregation processes, for example, material data can be determined more precisely and the behavior of metal alloys and semiconductors can be investigated in zero gravity. Samples can be melted at temperatures between 400 and 2000 °C. The material data is recorded using a high-speed camera and a pyrometer (radiation thermometer).
The EML system was developed by Airbus Defence and Space on behalf of the European Space Agency (ESA) and the Space Administration2 of the German Aerospace Center (DLR). The EML is controlled and monitored by the DLR Microgravity User Support Center (MUSC) in Cologne. Since its commissioning, the EML facility has achieved valuable results in the field of materials science research and will continue to be supported by the clients ESA and DLR in the future and expanded with new functionalities.
Armin Kayser, Managing Director of Kyocera Fineceramics Solutions, is very pleased about the cooperation: "Being part of such a large and prestigious project fills us with pride.
It shows that our hard and varied work in the field of ceramics is valued internationally and helps to drive research forward".
1 ESA Contract 21788/08/NL/BJ [EML (Electro-Magnetic Levitator) Phase B2/C/D Development] - Contract Change Notice 49 [EML OCS (Oxygen sensing and Control System) Phases C/D/E1 Development
2 DLR Space Administration Contracts 50WP0505, 50WP0606, 50WP0808
