Nikolai Alekseevich Rynin (23 December 1887 – 28 July 1942) was a Russian civil engineer, teacher, aerospace researcher, author, historian, and promoter of space travel.

During his career he performed research in aeronautics, became a balloonist and aircraft pilot, taught aerospace topics as a professor in Leningrad, and wrote various books and articles on airplanes and space travel.

[1] In the April 1918 issue of the Byloye magazine, Rynin published Nikolai Kibalchich's description of a manned, rocket-propelled ship.

It had been detailed in Kibalchich's final letter, and had languished in police archives until Rynin heard rumors of the design and fished it out.

[3] Rynin died from a combination of starvation and illness during the German siege of Leningrad, as did fellow spaceflight promoter Yakov Perelman.