Man must at all costs overcome the Earth's gravity and have, in reserve, the space at least of the Solar System.

Man must at all costs overcome the Earth's gravity and have, in reserve, the space at least of the Solar System.

人类必须不惜一切代价克服地球引力，至少保留太阳系的空间。

-- Konstantin Tsiolkovsky 齐奥尔科夫斯基