Kyocera supplies ISS experimental optical communications

Kyocera’s Fine Cordierite ceramic mirror has been adopted in the optical communication antenna, Quantum-Small Optical Link (QSOL), developed by Sony Computer Science Laboratories. Developed following a commission from Japan’s Ministry of Internal Affairs and Communications, QSOL is an optical communication antenna component for the Secure Laser Communications Terminal for Low Earth Orbit, "SeCRETS", for on-orbit technology demonstration.

This demonstration was conducted jointly by the National Institute of Information and Communications Technology (NICT), the School of Engineering, the University of Tokyo, the Next Generation Space System Technology Research Association, SKY Perfect JSAT Corporation, and Sony CSL.

Background of material selection

The current method for two-way data communication between Earth observation satellites in space and ground stations involves using optical wireless communication with either radio waves or visible light. This communication is essential for acquiring image data for weather forecasting, disaster response, and infrastructure monitoring.

Advancements in the sensors installed on Earth observation satellites have resulted in an increased volume of obtainable observation data. However, there is a pressing need to rapidly transmit large amounts of observation data to ground stations. Achieving high-speed and high-capacity data communication has posed a challenge for space infrastructure. To address this issue, the implementation of laser-light optical communication is expected to enable data transmission and reception at speeds over 100 times faster than radio wave communication with significantly higher capacity.

Additionally, to transmit data from satellites to specific ground stations by optical communication, it is necessary to adjust the light to the optimal angle using optical mirrors. Conventionally, metal or glass mirrors have been used, but nanoscale precision is required for adjusting light. Therefore, mirrors with long-term stable dimensional accuracy and the ability to withstand thermal expansion and temperature changes in the harsh space environment are needed.

In this experiment, Kyocera's Fine Cordierite ceramic mirror was installed in QSOL due to its unique thermal and mechanical properties, such as low thermal expansion and long-term dimensional stability.

With the success of this experiment, we believe that our products can contribute to the construction of space infrastructure aimed at achieving high-speed and high-capacity data communication in satellite optical communication in the future.

Kyocera will continue to leverage its fine ceramic technology to develop reliable components that contribute to research and observation in the fields of astronomy and space.

Features of Kyocera’s Fine Cordierite ceramic mirror

Kyocera’s Fine Cordierite ceramic mirror possesses the following four properties, achieved through our fine ceramic material and firing technology developed over more than 65 years to enable stable optical communication even in space.

• Low thermal expansion: The expansion and dimensional changes due to temperature variations are extremely small, making it possible to apply them to optical mirrors that require nanoscale precision.
• High mechanical strength and high rigidity: Compared to low thermal expansion glass, Kyocera’s Fine Cordierite ceramic mirror has 1.5 to 2 times higher mechanical strength, offering greater rigidity compared to glass and enabling weight reduction.
• Long-term dimensional stability: Fine Cordierite exhibits excellent dimensional stability compared to low thermal expansion glass, allowing for use over extended periods without concern for dimensional changes.
• Radiation resistance: Testing for radiation exposure confirmed that Fine Cordierite's coefficient of thermal expansion (CTE) remains unchanged, making it ideal for space applications.