Das Neue Universum (The New Universe) was a German science annual series aimed at older children.
From the German Wikipedia site (translated) : "The New Universe is a German children's literature series with themes in the fields of knowledge , research , adventure and entertainment . In addition to factual topics , Das Neue Universum also publishes fictional texts, e.g. by Isaac Asimov , Hans Dominik , and Michael K. Iwoleit . The choice of topic and content design were traditionally characterized by optimism about the future , science and feasibility from – nowadays also supplemented by more critical elements. While early volumes were aimed at the "mature youth" as a target group, today's readership, according to the publisher, consists of young people aged 15 and over and adults. Published since 1880 with 120 volumes up to 2020."
This annual had many interesting spaceflight articles over the years. In this 1950 volume (#67) they highlighted space stations with an article about a fictional voyage, with factual data.. They had a beautiful fold-out illustration in the front of the book. My friends shared their copy with me, which they treasured growing up.