In the book "Scouts of the Outer Planets: The Journey of the Pioneers and Voyagers from Earth to Neptune and Beyond," Igor Lisov sets out in exciting detail the history of the preparation, planning, financing, launches and flights of the Pioneers and Voyagers - spacecraft whose mission was to explore the planets of the outer solar system. These expeditions made it possible to obtain incredibly valuable information about Jupiter, Saturn, Uranus and Neptune - celestial bodies, the knowledge of mankind about which was previously very superficial. Two Voyagers are still in flight to this day: gradually losing power, they stop giving signals and move farther from Earth, outside the solar system. These ships are never destined to go back, but on board the Voyagers carry messages from earthlings to unearthly civilizations - in case such a meeting ever takes place.