70s of this century, humanity has long abandoned fossil fuels generating energy exclusively through nuclear fusion from Helium-3 but the hyper-exploitation of the Moon and asteroids threatens to leave humanity short of energy or bring it back to the pollution generated by fossil fuels. For this reason the Italian Space Agency, after having created ground and orbiting outposts on the Moon, Mars and Jupiter as well as extraction points on the main asteroids of the belt of the same name between Mars and Jupiter, decides to go to the limits of the solar system where the parents of young Leonardo identify a mysterious object whose mass could be 10 times that of Jupiter but disappear into thin air in an attempt to track it down. When their only son grows up he decides to embark on the same career as them with the aim of finding them therefore he begins a hard two-year training in Sicily during which he will have to prove that he has what it takes to become an astronaut, on the island he will come across those who they will be part of his crew with whom he will form a strong bond of friendship, i.e. Orlando, Lucia, Chiara and Alice. He will also meet Sofia with whom he will embark on a love relationship, marrying her before leaving for his first mission. Looming over the success of his intentions is Pandora, a complex artificial intelligence used by the Space Agency to make life easier for astronauts but which in reality will turn out to be much more. The title of the work is "Odyssey - Part I" and represents the first part of a cycle of four novels of which Part I is set on Earth, Part II on the Moon and Mars, Part III in the belt of gas giants and part IV in the Kuiper belt. This Part I narrates the two years of training that aspiring astronauts must undergo before being able to travel among the stars, describes all the systems used for space travel and describes the first space mission that Leonardo and his companions will undertake around the Earth.