Is the story of Zigmond Jahn (the first German astronaut) in Goodbye Lenin true?

Sigmund Werner Paul Jaumlhn (German: Sigmund Werner Paul J? Hn, 1937 February 13-), Major General of the East German Air Force. Because East Germany participated in the "International Cosmic Project (Russian: интеркосмос)" led by the Soviet Union, it became the first German astronaut.

1976, Sigmund Jahn and his replacement eberhard Kohler were selected as astronauts in the international space project. After two years of professional training, he took off on the Soyuz -3 1 spacecraft on August 26th, 65438, and successfully docked with the Soviet Salute -6 space station. During this period, he and the astronauts of the space station carried out many scientific experiments, and took the Soyuz -29 spacecraft on September 3, 1978. This is well known to women and children in the GDR.