For us cosmonauts, the prophetic words of Tsiolkovsky on the opening up of outer space will always be our program, will always summon us forward
Yuri Gagarin

Konstantin Eduardovich Tsiolkovsky ─ the greatest Russian researcher, an outstanding theorist in the field of aeronautics, aviation and astronautics, was born on September 17, 1857. Multistage rocket, liquid jet engine, space stations and many other things were invented and predicted in the works of Tsiolkovsky back in the 19th – early 20th century, when a flight into space could hardly be seriously dreamed about. Tsiolkovsky also predicted the creation of the laser, inexhaustibility of the atom, independently built the Montgolfier, proposed a project of a metal-clad airship. A modest Kaluga teacher and self-taught scientist, Tsiolkovsky presented his ideas in the form of science fiction, philosophical works, etc.

“Konstantin Eduardovich called himself a citizen of the universe, but Tsiolkovsky is not only about cosmonautics and aeronautics, not only about engineering and philosophical heritage, but also about 40 years of teaching; he was also a great athlete, who mastered bicycling at 40, and an amazing grandfather to six grandchildren, who showed them constellations, fixed broken dolls and made kites. This is all about the great Tsiolkovsky,” said the great-granddaughter of the scientist A. E. Timoshenkova.

Entire Russian rocket engineering is based on Tsiolkovsky's ideas. He was the one to derive the equation linking rocket and fuel masses and gas exhaust velocities from the jet nozzle and the rocket itself ─ the famous Tsiolkovsky rocket equation. On the sheet with the equation, he put the date: May 10, 1897. This date can be considered as the beginning of the space era in the history of mankind.

Based on:

https://scientificrussia.ru/historical-events/17-sentabra-1857-goda-rodilsa-konstantin-eduardovic-ciolkovskij

https://scientificrussia.ru/articles/moi-korni-lezhat-v-ryazanskoj-zemle

https://gmik.ru/tsiolkovskiy/

Photos in the article, including photo on the homepage: https://ru.123rf.com