Sergey Prokudin-Gorsky
Sergey Mikhaylovich Prokudin-Gorsky (, ;  – September 27, 1944) was a Russian chemist and photographer. He is best known for his pioneering work in colour photography and his effort to document early 20th-century Russia.
Konstantin Tsiolkovsky
Only late in his lifetime was Tsiolkovsky honored for his pioneering work. In particular, his support of eugenics made him politically unpopular. However, from the mid 1920s onwards the importance of his other work was acknowledged, and he was honoured for it and the Soviet state provided financial backing for his research. He was initially popularized in Soviet Russia in 1931–1932 mainly by two writers: Iakov Perel'man and Nikolai Rynin. Tsiolkovsky died in Kaluga on 19 September 1935 after undergoing an operation for stomach cancer. He bequeathed his life's work to the Soviet state.