The nation’s first astronaut Yi Soyeon has pledged to do her best to fulfill the wishes of the Korean people when she travels into space next month.

Yi has replaced the nation’s would-be first astronaut Ko San, who had broken training rules in Russia. In a letter to the Korea Aerospace Research Institute, Yi said she was surprised by the sudden replacement.

Yi promised to meet public expectations by fulfilling her duties as an astronaut and contributing to the nation’s scientific development.

Meanwhile, Ko publicly apologized for breaking the training rules and disappointing his supporters.

Ko will continue to train as a backup.