Thanks for the suggestion. I found it in the ARD-Mediathek. My vacation begins tomorrow and now I have something to listen to on my train ride to Vienna (which hopefully will leave the station).
2080: https://querschnitt.tumblr.com/
https://www.hoerspielprojekt.de/genre/science-fiction/
https://timeshift.blackdays.de/
https://www.serotonin-audio.de/
https://www.gratis-hoerspiele.de/alle-kostenlosen-science-fi...
there is also a 20GB torrent with lots of 1-hour german radio episodes. you can find it under the name: "german_audiobooks_radio-science-fiction". there are more of those on youtube.
and for star trek fans there is the german series eberswalde. http://www.raumschiff-eberswalde.com/
there is of course 10 times more in english...