Yuri Kondratyuk

A pioneer of astronautics and spaceflight, a theoretician and a visionary who, in the early 20th century, developed the first known lunar orbit rendezvous (LOR), a key concept for landing and return spaceflight from Earth to the Moon.

I don't remember now how I found out about him. Probably, one of the professor at the University metioned him. But most likely, I googled about him after watching Taming of the fire, where the main character says how he learned everything from Tsiolkovskiy and Kondratyuk, which is, of course, not true, but still sweet, that after so many years of suppression, Soviets finally recognized his work.

I really love the title of his book "To those who would read when building" (rus: Тем, кто будет читать, чтобы строить). In 1965, his books were translated by NASA and some of his ideas, such as the use of a modular spacecraft to reach the Moon, leaving the propulsion section of the vehicle on orbit while a smaller lander journeyed to the surface and back, were eventually adopted by the engineers of the Apollo program.

It amazes me how productive he was despite all circumstances. Russian revolution forced him to change his name. For his grain elevator, built without a single nail, he was sentenced to three years in GULAG, but was sent to sharashka (research facility prison) instead. He had to refuse offer from Sergei Korolev fearing NKVD would reveal his true identity. His project of a large wind turbin was shut down overnight because of political games after being 4 years into developing.

See also