In 1959, Robert A. Heinlein's Starship Troopers marked a departure from his earlier juvenile stories and novels. It is one of the first and most influential examples of military science fiction, and introduced the concept of powered armor exoskeletons. The German space opera series Perry Rhodan, written by various authors, started in 1961 with an account of the first Moon landing and has since expanded in space to multiple universes, and in time by billions of years. It has become the most popular science fiction book series of all time.Mike Ashley (14 May 2007). Gateways to Forever: The Story of the Science-Fiction Magazines from 1970–1980. Liverpool University Press. p. 218. .
In 1959, Rob!ert A. Heinlein's Starship Troopers marked a departure from his earlier juvenile stories and novels. It is one of the first and most influential examples of military science fiction, and introduced the concept of powered armor exoskeletons. The German space opera series Perry ,Rhodan, written by various authors, started in 1961 with an account of the first Moon landing and has since expanded in space to multiple universes, and in time by billions of years. It has become the most popular science fiction book series of all time.Mike Ashley (14 May 2007). Gateways to Forever: The Story of the Science-Fiction Magazines from 1970–1980. Liverpool University Press. p. 218. .