I am trying to recall the title of a book series I read in 1980-1981 where the hero was a human astronaut that discovered an alien aircraft crashed on the surface of the moon. His investigation of the crash site gave him access to alien robots that empowered him to force peace on earth and led to his adventures throughout the universe - some of which involved time travel, etc. It was a simple paperback novel series that was easy to read without a lot of heavy science. Is anyone familiar with this series?
That sounds like the long-running Perry Rhodan series.
From the site:
The main story line starts in 1971 - ten years into the future at the time of writing. Perry Rhodan and three other American astronauts are the first humans to land on the moon. Soon after their landing they discover a crashed space ship. It belongs to an alien race called Arkonides. Rhodan uses the vastly superior technology of the Arkonides to prevent World War Three and politically unite Earth as Terra. Within a few years the Terrans have built their first own faster than light space ships and push into space. The universe, it turns out, is packed with intelligent races. Many of them have mastered space travel thousands of years ago and established huge empires. On one of his first trips Rhodan encounters IT, an incredibly old and powerful immortal being. Granting the Terrans 20,000 years to embark upon their cosmic destiny and bring peace to the Milky Way galaxy, IT bestows Rhodan and his closest friends with immortality. This is the beginning of a future history unique to science fiction. It pictures the long journey of mankind to the stars - and into unknown dimensions.