BERLIN — Sigmund Jähn, whose distinction as the first German to travel into space made him a Cold War symbol of socialist unity at a time when East and West Germany competed for national achievements, died on Saturday in Strausberg, Germany, outside Berlin. He was 82.

The German Aerospace Center confirmed the death but did not specify a cause.

On Aug. 26, 1978, Mr. Jähn and the Russian cosmonaut Valery Bykovsky left Earth aboard the Soyuz 31 and spent seven days, 20 hours and 49 minutes in space, most of it aboard the Salyut 6 space station.

Their mission was to dock and resupply the Salyut 6 and run biological and medical experiments alongside the station’s long-duration crew, Vladimir Kovalyonok and Aleksandr Ivanchenkov. Mr. Jähn and Mr. Bykovsky returned to Earth on the Soyuz 29, the spacecraft the other crew had come up on.

“Dear TV audience of the German Democratic Republic,” Mr. Jähn said in a radio transmission from the space station in 1978. “I’m very happy to be allowed to be the first German to take part in this manned spaceflight.”