Yamazaki earned a Master of Engineering degree from the University of Tokyo in 1996 and began her career at the Japan Aerospace Exploration Agency (JAXA). She was selected as an astronaut candidate in 1999, qualified as a Soyuz flight engineer in 2004, and became a NASA-certified mission specialist in 2006.
In April 2010, Yamazaki flew aboard Space Shuttle Discovery as a mission specialist on STS-131, an assembly and resupply mission to the International Space Station (ISS).
After retiring from JAXA in 2011, she served as a member of the National Space Policy Committee of the Cabinet Office of Japan (2012–2022). She currently chairs the Subcommittee on Space Development and Utilization at the Ministry of Education, Culture, Sports, Science and Technology (MEXT).
In 2018, Yamazaki co-founded the Space Port Japan Association and has since served as its representative director, working to promote the space industry in Japan. Since 2021, she has been dedicated to educating the next generation as president of the Young Astronaut Club Japan. She also serves on the Council of The Earthshot Prize, launched in 2020 by the Prince of Wales and The Royal Foundation, to inspire a decade of action to repair our planet. She has served in roles such as General Manager of Vast Japan, which is involved in the development of commercial space stations since 2025. She holds a Ph.D. in Engineering from the University of Tokyo.

Seiko Shirasaka received his M.S. in Aeronautics and Astronautics from the University of Tokyo and his Ph.D. in Systems Engineering from Keio University.

After completing his master’s degree, he joined Mitsubishi Electric Corporation, where he spent 15 years engaged in space development. He participated in the development of a number of space systems, including the H-II Transfer Vehicle (HTV), “KOUNOTORI.” In particular, he was involved in the HTV program from its early design phase through the successful completion of the first flight mission. The HTV development team received numerous awards for its achievements.

He later served as a Program Manager for the Cabinet Office’s Impulsing Paradigm Change through Disruptive Technologies Program (ImPACT), where he led the development of an on-demand small Synthetic Aperture Radar (SAR) satellite system.

He co-founded Synspective Inc., a space startup specializing in small SAR satellites and satellite data solutions. Synspective received the Minister of Education, Culture, Sports, Science and Technology Award at the Japan Startup Awards 2022.

He has also contributed extensively to government policy and programs as a member or chair of numerous committees. His roles have included serving as a member of the Cabinet Office’s Committee on National Space Policy; a member of the Aviation and Space Working Group and the Ocean Working Group, and Chair of the Materials Working Group, under the Cabinet Secretariat’s Council of Growth Strategy; Supervising Program Officer (PO) for the Space Exploration Domain of the Space Strategy Fund; and Chair of the Manufacturing Industries Subcommittee of the Industrial Structure Council at the Ministry of Economy, Trade and Industry (METI), among many other positions.