Kyocera Installs World's First*1 Fine Cordierite Ceramic Mirror for International Space Station Experimental Optical Communications | News | Editorial

Kyocera Corporation (President: Hideo Tanimoto, hereinafter: Kyocera) announced that its “Fine Cordierite” ceramic mirror has been selected for use in equipment to perform optical communication between the International Space Station (ISS) and a mobile optical station on Earth. This is the first time^*1 that cordierite was adopted for such a purpose.

*1 The first time a mirror made of cordierite ceramic was selected for use in optical communication equipment on the ISS, based on Kyocera research (2024)

For more information about Kyocera's Fine Cordierite ceramic mirror, please see:
https://www.youtube.com/watch?v=1xf-m8gz7yM

Excellent Kyocera cordier ceramic mirror

Kyocera's Fine Cordierite ceramic mirror is adopted in the optical communication antenna (Quantum-Small Optical Link, hereafter: QSOL) developed by Sony Computer Science Laboratories, Inc. (President and CEO: Hiroaki Kitano, hereafter: Sony CSL). Developed following a commission from Japan's Ministry of Internal Affairs and Communications, the QSOL is an optical communications antenna component for the Secure Low Earth Orbit Laser Communications Terminal, SeCRETS, for on-orbit technology demonstration.

This demonstration was jointly conducted by the National Institute of Information and Communication Technology (President: Hideyuki Tokuda, hereafter: NICT), School of Engineering, University of Tokyo (Dean: Yasuhiro Kato), Space System Technology Research Association of Next Generation (President: Koji Yamaguchi), SKY Perfect JSAT Corporation (Representative Director, President and Chief Executive Officer: Eiichi Yonekura) and Sony CSL.

Material selection background

The current method for two-way data communication between Earth observation satellites in space and ground stations involves the use of wireless optical or radio wave or visible light communication. This communication is essential for acquiring image data for weather forecasting, disaster response and infrastructure monitoring.
Advances in sensors installed on Earth observation satellites have resulted in an increased volume of accessible observational data. However, there is an urgent need to rapidly transmit large amounts of observational data to ground stations. Achieving high-speed, high-capacity data communications has presented a challenge for space infrastructure. To address this issue, the implementation of optical laser light communication is expected to enable the transmission and reception of data at speeds over 100 times faster than radio wave communication with significantly higher capacity.

For more, to transmit data from satellites to specific ground stations by means of 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 light regulation. Therefore, mirrors with stable long-term dimensional accuracy and the ability to withstand thermal expansion and temperature changes in the harsh environment of space are needed.

In this experiment, the Kyocera Fine Cordierite ceramic mirror was installed in the 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 optical satellite communication in the future.
Kyocera will continue to use its Fine Ceramic technology to develop reliable components that contribute to research and observation in the fields of astronomy and space.

Features of Kyocera 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.

(1) Low thermal expansion

Expansion and dimensional changes due to temperature changes are extremely small, making possible their application in optical mirrors that require nanoscale precision.

(2) High mechanical strength and high stiffness

Compared to low thermal expansion glass, Kyocera's Fine Cordierite ceramic mirror has 1.5 to 2 times higher mechanical strength, providing greater stiffness compared to glass and enabling weight reduction.

(3) Long-Term Dimensional Stability

Fine Cordierite exhibits excellent dimensional stability compared to low thermal expansion glass, allowing long-term use without worrying about dimensional changes.

(4) Resistance to radiation

Radiation exposure testing confirmed that Fine Cordierite's coefficient of thermal expansion (CTE) remains unchanged, making it ideal for space applications.

Kyocera will exhibit its Fine Cordierite ceramic mirror at SPIE Astronomical Telescopes and Instrumentation 2024to be held at Pacifico Yokohama (Yokohama City, Japan) from June 18 to June 20. (Stand no. 314)

About SPIE 2024 telescopes and astronomical instruments
https://spie.org/conferences-and-exhibitions/astronomical-telescopes-and-instrumentation

For more information about the Kyocera cordierite ceramic mirror, please see:
https://global.kyocera.com/prdct/fc/product/category/life/life010.html

About the Experiment

SeCRETS launched to the ISS on August 2, 2023 and was installed on the external experiment platform of the Japanese Experiment Module “Kibo” (Intermediate Space Environment Experiment Platform [i-SEEP]). Secret key sharing was then performed using 10 GHz clock optical communication from the ISS in low orbit to a portable optical ground station on the ground, and further successfully demonstrated secure communication between the ISS and the ground station using encryption of one time lock with key*2.

*2 successfully achieved secret key sharing and highly secure communication between the ISS and earth. “Raising Expectations for the Practical Application of Satellite Quantum Encryption”.
https://www.sonycsl.co.jp/press/prs20240418/ (Japanese only)

Demonstration diagram

3 Image by: Sony Computer Science Laboratories

The Secure Low Earth Orbit Laser Communications Terminal, “SeCRETS”,
equipped with Kyocera's Fine Cordierite Ceramic Mirror

4 Image by: National Institute of Information and Communication Technology, Sony Computer Science Laboratories, Next Generation Space System Technology Research Association

For more information about the experiments:
https://www.sonycsl.co.jp/press/prs20240423/?lang=en

SeCRETS was developed as part of the Ministry of Internal Affairs and Communications “Research and Development Project for Key ICT Technologies (JPMI00316),” specifically under “Research and Development of Quantum Cryptography Technology in Satellite Communications (JPJ007462).”

(Reference) Press release of the Ministry of Internal Affairs and Communications dated 14.06.2018
Results of the Public Offer for Research and Development Proposals in the field of Information and Communication Technology 2018

http://www.soumu.go.jp/menu_news/s-news/01tsushin03_02000247.html