Talk of space stations,space manufacturing or space defense will be whimsy until the cost of reaching orbit comes down(Gregg Easterbrook.是什么意思_Talk of space stations,space manufacturing or space defense will be whimsy until the cost of reaching orbit comes down(Gregg Easterbrook.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句