Deutsche Demokratisch Republik 10th Anniversary of the Soviet-DDR Manned Spacefligh

DEUTSCHE DEMOKRATISCH REPUBLIK issued a First Day Cover stamp on 24 June 1988 to commemorate the 10th anniversary of the joint Soviet-DDR manned spaceflight. The stamp featured cosmonauts Sigmund Jähn and Valery Bykovsky who manned the joint spaceflight. Sigmund Jähn, the first German in space, is seen  signing the returned space capsule. The stamp had a face value of 5 DDR Pfennig.

Jähn, an East German Air Force pilot, flew aboard the Soviet spacecraft Soyuz 31 to the Salyut 6 space station on 26 August 1978. He was accompanied by Soviet cosmonaut Valery Bykovsky. The mission was part of the Soviet Intercosmos programme and lasted for nearly eight days. 

During his time in space, Jähn performed various scientific experiments. These included technical experiments with the MKF-6 multispectral camera for remote sensing of the Earth's surface, material science experiments on crystallization, like the formation, recrystallization, and the cultivation of a monocrystal. He also conducted medical experiments on how weightlessness affects speech, occupational psychological studies, testing the hearing sensitivity of regular crew members, biological experiments on cellular growth under weightlessness, and the connection between microorganisms with organic polymers and inorganic substances.

As of 2024, twelve German astronauts have travelled to space and conducted scientific research. Dr. Ulf Merbold was the first West German in space and the only German to have made the journey the most often -- three times