In 2010, she started an MBA program at the Haas School of Business at the University of California, Berkeley[3] In 2015 she taught engineering physics at Everett Community College in Washington State.

On September 5, 2007, the Korean Ministry of Science and Technology selected Ko San as the primary astronaut, and Yi So-yeon as backup, following performance and other tests during their training in Russia.

[12] During her mission, Yi So-yeon carried out eighteen science experiments for KARI and conducted interviews and discussions with media.

Other experiments involved the growth of plants in space, the study of the behaviour of her heart, and the effects of gravity change on the pressure in her eye and shape of her face.

[16] At the end of the mission, Yi returned to Earth along with ISS crew members Peggy Whitson and Yuri Malenchenko aboard Soyuz TMA-11, on April 19, 2008.

Due to a malfunction with the Soyuz vehicle, the craft followed a ballistic re-entry which subjects the crew to severe gravitational forces up to 10 times the amount experienced on Earth.

[19] On October 4, 2008, Yi launched the International Institute of Space Commerce at a ceremony held in Douglas, Isle of Man.

[21] On August 13, 2014, the Korean Aerospace Research Institute announced Yi's resignation for personal reasons, ending the country's space program.

[22] After receiving her MBA from the University of California, Berkeley Haas School of Business, Yi joined the Association of Spaceflight Professionals.