Chiaki Mukai (向井 千秋 Mukai Chiaki, born May 6, 1952, Tatebayashi, Gunma, Japan) is a Japanese doctor and JAXA astronaut. She was the first Japanese woman in space, and was the first Japanese citizen to have two spaceflights. Both were Space Shuttle missions; her first was STS-65 aboard Space Shuttle Columbia in July 1994, which was a Spacelab mission. Her second spaceflight was STS-95 aboard Space Shuttle Discovery in 1998. In total she has spent 23 days in space.