Life

Chiaki Mukai was born on May 6th, 1952 in Tatebayashi City, Gunma, Japan.¹ At nine years old, a young Mukai read about Russian astronaut Yuri Gagarin’s launch into orbit, the first human to travel into space in April 1961² and Russian astronaut Valentina Tereshkova becoming the first woman in space in June 1963.³ Mukai was inspired, even more so because Japan didn’t have space travel infrastructure compared to the US and Soviet Union.⁴ Because there were no opportunities in Japan for astronautical training, Mukai thought that becoming one was “impossible”. So, she pursued a different career, one in medicine. 

Mukai graduated from Keio University School of Medicine and became board-certified, practicing from 1977 to 1978.⁵ During this time, Dr. Mukai was a surgical resident at Keio University Hospital. In 1978, she worked in general surgery at Shimizu General Hospital and then emergency surgery at Saiseikai Kanagawa Hospital in 1979.⁶ Dr. Mukai came back to Keio University Hospital as a cardiovascular surgery resident in 1980 but left in 1982 to work on the cardiovascular surgery staff at Saiseikai Utsunomiya Hospital. After working at different hospitals around Japan, Dr. Mukai brought her medical experiences back to Keio University Hospital in 1983 to become the Chief Resident in Cardiovascular Surgery.⁷

In 1985, Dr. Mukai’s professional career extended to space. She started as a National Space Development Agency of Japan (NASDA) science astronaut and visiting scientist for the Division of Cardiovascular Physiology at NASA Johnson Space Center in Houston, working in research and education at Baylor College of Medicine.⁸ Simultaneously, she was also serving as a visiting professor of the Department of Surgery at Keio University. ⁹ Before her eventual space flight opportunities, Dr. Mukai worked as a ground communicator for the STS-47 mission in 1992. The STS-47 First Material Processing Test selected three Japanese Payload Specialists, marking the introduction of Japan into American space flight.¹⁰ At age 32, she was selected by the Japanese Aerospace Exploration Agency (JAXA) for the position of Payload Specialist on the STS-65 mission aboard the space shuttle “Columbia”.¹¹ STS-65 was NASA’s First Material Processing Test (FMPT).¹² JAXA describes the responsibilities of payload specialists as “individuals other than NASA astronauts (commanders, pilots, and mission specialists), whose presence is required on board the Space Shuttle to perform specialized functions concerning the operation of one or more payloads or other essential mission activities.”¹³ JAXA also states that it operates as an integral member of the mission, responsible for certain operations, such as solving equipment malfunctions, operating equipment, and generally supporting the mission with food, hygiene systems, and emergency procedures.¹⁴ To summarize, payload specialists have specific tasks related to the different payload operations occurring on the same mission and to support the rest of the crew with essential workings inside the aircraft. STS-65 was the second International Microgravity Laboratory (IML) flight and conducted 82 Space Life and Microgravity Science experiments. Dr. Mukai’s mission specifically focused on the cardiovascular and autonomic nervous system and she utilized her great expertise in the cardiovascular surgery field to carry out these experiments.¹⁵ Through her participation in the STS-65 mission, Dr. Mukai became the first Japanese person to fly in space (twice!).¹⁶

Her second flight to space, STS-95 Discovery in 1998, was a monumental mission for the U.S., notable for US Senator John Glenn’s accomplishments as the first American astronaut to orbit Earth.¹⁷ Named by NASA, research on the Spartan solar observing spacecraft (studying solar wind), the Hubble Space Telescope Orbital Systems Test Platform, and biomedical observations on space flight and aging were all goals of STS-95.¹⁸

While the STS-95 concluded Dr. Mukai’s time in space, she continued her dedication of life sciences and space, working on the early 2000s STS-107 mission as a deputy mission scientist, coordinating research and experiments that would take place.¹⁹ Following her astronautical career, Dr. Mukai continued to research and teach in the U.S., Japan, and beyond. In 2004, Dr. Mukai worked as a visiting professor at the International Space University in France. Dr. Mukai’s relations with France earned her the French Legion of Honor award for her contributions to the Japan-France aeronautical relationship in 2015.²⁰ Her later career was spent with JAXA, being appointed as the Director of the Space Biomedical Research Office in 2007, a senior advisor to the JAXA Executive Director in 2011, the Director of the JAXA Center for Applied Space Medicine and Human Research in 2012, and finally, became a JAXA Technical Counselor in 2015. Dr. Mukai’s entire career was spent between research and education, upheld during her many promotions at JAXA post-space flight. In 2014, Dr. Mukai was appointed to the Ministry of Education, Culture, Sports, Special and Technology Subcommittee and in 2015, became the Vice President of the Tokyo University of Science.²¹ Her position included the responsibilities of  “the promotion of internationalization and promotion of women’s affairs”.²²

Her impact on biomedical and space research is significant. Credited with over sixty publications, Dr. Mukai is a household name not only in modern space and biomedical science but also in international relations. Dr. Mukai holds a seat on the United Nations Committee on the Peaceful Uses of Outer Space.²³ Dr. Mukai’s skills in medicine, teaching, research, and technical expertise acquired in 566 hours in space is incredibly unique. Her humble upbringing as an aspiring Japanese student interested in advancements outside her country to facilitate scientific collaboration internationally continues to be an inspiration to many.

Research

Effects of space flight on the histological characteristics of the aortic depressor nerve in the adult rat: electron microscopic analysis²⁴

This 2004 study measured the aortic barometric system of rats on Earth versus rats born in microgravity. The study concluded that mammals exposed to microgravity display decreased blood pressure and changes in nervous system activity. The goal of the study was to determine the health risks astronauts face during short-term microgravity exposure. 

Left: “Fine structure of a cross-section of the left aortic depressor nerve fascicles in the adult rat”

Right: “High-magnified electron microphotographs of a cross-section of the aortic depressor nerve”

Acclimation during space flight: effects on human physiology²⁵

This 2009 collaborative study observed the changes in physiology caused by extended exposure to microgravity. With technological advances, long-term space flight became possible with little understanding of the health effects. The study covered the “physiologic acclimation and acclimatization experienced by astronauts from launch to after return to earth”, including fluid redistribution, muscle changes, bone demineralization, and psychosocial effects. The other focus was on “countermeasures to minimize risks to astronauts before, during, and after spaceflight”. These observations included strategies to combat the previously mentioned observed effects on the astronauts. However, the findings were based on short-term space flight with the end goal being the development of countermeasures for the effects of long-duration space flight on the human body.

The Space-flight Environment: the International Space Station and Beyond²⁶

One more example of Dr. Mukai’s scientific contributions is a collaborative 2009 publication on the space-flight environment’s effect on the human body, forging a path for the safety of future astronauts. Radiation and microgravitational environments pose the largest threats to astronauts and these findings influenced the production of updated spacesuit designs. However, long-term space flight is most concerning regarding irreversible health effects such as cancer or eye damage. 

Chiaki Mukai’s Honors & Awards

• Outstanding Service Award – The Society of Japanese Women Scientists (1996)
• Special Congressional Recognition – U.S. Congress (1995)
• Happy Hands Award – Satte Junior Chamber of Commerce (1995)
• Aeromedical Association of Korea Honorary Membership (1995)
• Tatebayashi Children Science Exploratorium Honorary President (1995)
• Prime Ministers Special Citation for Contributions to Gender Equality (1995)
• The De La Vaux Medal – The Federation Aeronautique Internationale(1995)
• The Award for Distinguished Service in Advancement of Space Biology – Japanese Society for Biological Sciences in Space (1995)
• Prime Ministers Special Citation (1994)
• Minister of State for Science and Technology Commendation (1994 & 1992)
• People of Gunma Prefectures Certificate of Appreciation (1994)
• Honorary Citizen of Tatebayashi City (1994)
• Outstanding Service Award – National Space Development Agency of Japan (1994 & 1992)
• Award for Distinguished Accomplishments – Tokyo Women’s Foundation (1994) 
• Commendation for Technology – Japan Society of Aeronautical and Space Science (1993).

Bibliography

“1-1-2-3 NASA Regulation.” Accessed October 9, 2024. https://www.jaxa.jp/library/space_law/chapter_1/1-1-2-3_e.html.

Boston, Japan Society of. “Chiaki Mukai.” JapanSocietyOfBoston, November 11, 2022. https://www.japansocietyboston.org/post/chiaki-mukai.

“Chiaki Mukai – the First Japanese Woman to Go to Space.” Accessed October 9, 2024. https://www.tohoku.ac.jp/en/news/university_news/interview_with_chiaki_mukai.html.

“First Woman in Space: Valentina.” Accessed October 9, 2024. https://www.esa.int/About_Us/ESA_history/50_years_of_humans_in_space/First_woman_in_space_Valentina.

JAXA Human Spaceflight Technology Directorate. “MUKAI Chiaki Astronauts.” Accessed October 9, 2024. https://humans-in-space.jaxa.jp/en/astronaut/mukai-chiaki/.

“Payload Specialist Astronaut Bio: Chiaki Mukai 10/03,” n.d.

Thirsk, Robert, Andre Kuipers, Chiaki Mukai, and David Williams. “The Space-Flight Environment: The International Space Station and Beyond.” CMAJ 180, no. 12 (June 9, 2009): 1216–20. https://doi.org/10.1503/cmaj.081125.

Tokyo University of Science. “Project Professor Chiaki Mukai’s Inauguration as Vice President of the Tokyo University of Science.” Accessed November 17, 2024. https://www.tus.ac.jp/en/news/archive/20150401.html.

Williams, David, Andre Kuipers, Chiaki Mukai, and Robert Thirsk. “Acclimation during Space Flight: Effects on Human Physiology.” CMAJ: Canadian Medical Association Journal = Journal de l’Association Medicale Canadienne 180, no. 13 (June 23, 2009): 1317–23. https://doi.org/10.1503/cmaj.090628.

Yamasaki, Masao, Tsuyoshi Shimizu, Masao Miyake, Yukako Miyamoto, Shin-Ichiro Katsuda, Hirotaka O-Ishi, Tadanori Nagayama, et al. “Effects of Space Flight on the Histological Characteristics of the Aortic Depressor Nerve in the Adult Rat: Electron Microscopic Analysis.” Uchu Seibutsu Kagaku 18, no. 2 (June 2004): 45–51. https://doi.org/10.2187/bss.18.45.

“Yuri Gagarin.” Accessed October 9, 2024. https://www.esa.int/About_Us/ESA_history/50_years_of_humans_in_space/Yuri_Gagarin.