I do not remember how it got into my head to make the first calculations related to rocket. It seems to me the first seeds were planted by famous fantaseour, J. Verne.

From the moment of using rocket devices, a great new era will begin in astronomy: the epoch of the more intensive study of the firmament.

My entire life consisted of musings, calculations, practical works, and trials. Many questions remain unanswered; many works are incomplete or unpublished. The most important things still lie ahead.

Mankind will not forever remain on Earth but, in the pursuit of light and space, will first timidly emerge from the bounds of the atmosphere and then advance until he has conquered the whole of circumsolar space.

The Earth is the cradle of humanity, but mankind cannot stay in the cradle forever.

Men are weak now, and yet they transform the Earth's surface. In millions of years, their might will increase to the extent that they will change the surface of the Earth, its oceans, the atmosphere, and themselves.