His epitaph, written by himself (translation): Man will not always stay on Earth; the pursuit of light and space will lead him to penetrate the bounds of the atmosphere, timidly at first, but in the end to conquer the whole of solar space.
Mentioned in Beyond the Planet Earth, by K. Tsiolkovsky (1920), translated by K. Syers (1960), reviewed by M. G. Whillans, Journal of the Royal Astronomical Society of Canada, Vol. 55 (1961), p. 144 
Translation: All the Universe is full of the life of perfect creatures.Konstantin Eduardovich Tsiolkovsky
Translation: The blue distance, the mysterious Heavens, the example of birds and insects flying everywhere are always beckoning Humanity to rise into the air.Konstantin Eduardovich Tsiolkovsky