While working as a mechanic, Yuri Kondratyuk completed the manuscript of a book titled The Conquest of Interplanetary Spaces, dealing with rocket motion and issues concerning the colonization of space. He also suggested using a gravitational slingshot trajectory to accelerate a spacecraft.[1] In 1925, Kondratyuk made contact with Moscow-based scientist Vladimir Vetchinkin and sent him the manuscript. Up to that time, he and his work were unknown to rocketry enthusiasts. While the book was enthusiastically received by scientists in Moscow, no publisher would touch such a fanciful work.
Eventually, Kondratyuk paid a Novosibirsk Siberian Union printing shop to produce 2,000 copies of the 72-page work,[2] and even then had to do much of the typesetting and operating the press himself, both to save costs but also because the equations in the book posed problems for the printer. Kondratyuk's discoveries were made independently of Konstantin Tsiolkovsky who also worked on spaceflight issues at that time; the two never met.
