Every exit is an entry somewhere else.
The only limit to our realization of tomorrow will be our doubts of today.
Man must rise above the Earth—to the top of the atmosphere and beyond—for only thus will he fully understand the world in which he lives.
Exploration is really the essence of the human spirit.
We shall not cease from exploration, and the end of all our exploring will be to arrive where we started and know the place for the first time.