Franz Viehböck was chosen for the Soviet-Austrian space project Austromir 91.
After two years of training, he was selected for the Soyuz TM-13 mission, and took off from the Baikonur cosmodrome on October 2, 1991 with Russian cosmonauts Alexander A. Volkov and Kazakh Toktar Aubakirov.
On board the Mir space station, together with cosmonauts Anatoly Artsebarsky and Sergei Krikalev, he undertook 15 experiments in the fields of space medicine, physics and space technologies.
Viehböck returned to earth on October 10, 1991 in the Soyuz TM-12 capsule after spending 7 days and 22 hours in space.
For the next two years he held many conferences on his mission, then went to the United States and worked for Rockwell. When Rockwell was taken over by Boeing, he became “Director for International Business Development” in Vienna.