Soyuz 31
The Soviet Union’s Soyuz 31 mission to the Salyut 6 space station lifts off, with cosmonauts Valery Bykovsky and Sigmund Jahn (the first East German space traveler) aboard. The crews are segregated less than on previous Interkosmos flights, and the Soyuz 31 crew is in space for over a week. They leave their vehicle at Salyut 6 and return in the Soyuz 29 vehicle on September 3rd.