"Perry Rhodan" is not a German name, I never considered that the series might be originally in German! They have many books of the series in the library here. I read one or two many years ago, from somewhere in the middle because the first few weren't available iirc, and I thought they were okay but not good enough to outweigh that I never felt connected to any of the characters because the books naturally assumed I knew a lot about them when I didn't. (I read a lot less fanfic in fandoms I don't know back then.) Basically all I remember is that Gucky was fun, and the immortality macguffins seemed like cheating.
Maybe I'll give it another try one day.