Which cosmonaut, Franz Viehböck and Sigmund Jähn, visited the Mir space station in 1991 aboard Soyuz TM-13?
Franz Viehböck: Franz Artur Viehböck (born August 24, 1960 in Vienna) is an Austrian electrical engineer, and was Austria's first cosmonaut. Franz Viehböck:  He visited the Mir space station in 1991 aboard Soyuz TM-13, returning aboard Soyuz TM-12 after spending just over a week in space. Sigmund Jähn: Sigmund Werner Paul Jähn (born 13 February 1937) is a German cosmonaut and pilot, who in 1978 became the first East German (and German native) to fly in space as part of the Soviet Union's Interkosmos programme.
Franz Artur Viehböck