I love science fiction and this makes it the perfect thing for me to read in order to learn German.
My favourite author at the moment is Andreas Brandhorst
His books are a mixture of hard science fiction with space ships, robots, etc. and a more than usually developed vision of psionic elements or what would be "the force" in Star Wars.
I especially like that his books are not available in English and so my new language skills are giving me an insight into science fiction I would not otherwise get.
I found some of his work on Amazon.co.uk
but nothing on Amazon.com
Of course a better place to get German books is the German Amazon, Amazon.de
who have many more of his books. They have the start of his new trilogy.
And a lot of books he has translated.