“The Earth is the cradle of humanity, but mankind cannot stay in the cradle forever.”
Other Konstantin Tsiolkovsky Quotes
Man must at all costs overcome the Earth's gravity and have, in reserve, the space at least of the Solar System.
Konstantin Tsiolkovsky 
58% of people like this quote
The Earth is the cradle of humanity, but mankind cannot stay in the cradle forever.
Konstantin Tsiolkovsky
44% of people like this quote