on the mirror field of the disc - a relief image of the State Emblem of the Russian Federation, above it along the edge - an inscription in a semicircle: "RUSSIAN FEDERATION", framed on both sides by double rhombuses, below the emblem: on the left - designations of precious metal and alloy samples, on the right - the content of chemically pure metal and the mint trademark, at the bottom in the center in three lines - the inscription: "BANK OF RUSSIA", coin denomination: "3 RUBLES", year of issue: "2021".

on the mirror field of the disk - a relief image of the portrait of K.E. Tsiolkovsky against the background of color images of outer space and formulas; at the bottom along the edging - the inscription: “K.E. TSIOLKOVSKY ".

300 corrugated

Konstantin Tsiolkovsky (1857–1935) was a self-taught scientist who became the founder of modern cosmonautics. His striving for the stars was not prevented by poverty, deafness, or isolation from the domestic scientific community. Being an eccentric and dreamer, Tsiolkovsky devoted all his strength to science. He sent his first scientific works "Theory of gases", "Mechanics of an animal organism" and "Duration of radiation of the Sun" to the capital. The learned world of that time (first of all, Ivan Sechenov and Alexander Stoletov) reacted kindly to the self-taught. He was even offered to join the Russian Physicochemical Society. Tsiolkovsky did not answer the invitation: he had nothing to pay membership dues with. Tsiolkovsky's main project at that time was an airship (the scientist decided to get away from the use of explosive hydrogen, replacing it with hot air, and the constriction system he developed allowed the "ship" to maintain constant lift at different flight altitudes), but Tsiolkovsky's interest in flying over the ground died away when he was interested in the stars. In 1903, Tsiolkovsky switched to work related to space exploration. In the article "Exploration of world spaces with jet devices" he first substantiated that a rocket could become an apparatus for successful space flights. The scientist also developed the concept of a liquid propellant rocket engine. In particular, he determined the speed required for the spacecraft to enter the Solar System ("second space speed"). Tsiolkovsky dealt with many of the practical issues of space, which later formed the basis for Soviet rocketry: he proposed options for rocket control, cooling systems, nozzle design, and fuel delivery systems.

Artists: E.V. Kramskaya (obverse), O. G. Shepel (reverse). Sculptors: A.A. Dolgopolova (obverse), O. G. Shepel (reverse).