月球很可能成为太阳系的工业中心，为其星际飞船供应火箭燃料，而这种燃料能够从月球岩石中以液态氧的形式轻易获取。
The Moon is likely to become the industrial hub of the Solar System supplying the rocket fuels for its ships, easily obtainable from the lunar rocks in the form of liquid oxygen.
原因在于月球的引力。
The reason lies in its gravity.
由于月球质量仅为地球的八十分之一，从月球飞行四分之一百万英里（约25万英里）至地球轨道，所需能量比从地球表面进入轨道的200英里飞行减少了97%！
Because the Moon has only an eightieth of the Earth's mass, it requires 97% less energy to travel the quarter of a million miles from the Moon to Earth-orbit than the 200 mile-journey from Earth's surface into orbit!
这听起来或许匪夷所思，但却很容易计算得出。
This may sound fantastic, but it is easily calculated.
若要乘火箭逃离地球，速度必须达到每秒七英里。
To escape from the Earth in a rocket, one must travel at seven miles per second.
从月球出发的对应逃逸速度仅为每秒1.5英里。
The comparable speed from the Moon is only 1.5 miles per second.
由于月球表面的重力仅为地球的六分之一（回想一下阿波罗宇航员行走时是多么轻松自如），加速到那每秒1.5英里所需的能量，远比在地球上加速所需的少得多。
Because the gravity on the Moon's surface is only a sixth of Earth's (remember how easily the Apollo astronauts bounded along), it takes much less energy to accelerate to that 1.5mps than it does on Earth.
月球居民将能够以其地球同类所需费用的区区3%，在太空中飞行。
Moon dwellers will be able to fly in space at only three percent of the cost of similar journeys by their terrestrial cousins.
阿瑟·C·克拉克曾指出，一个革命性的想法要经历三个阶段：第一阶段，"这是不可能的——别浪费我的时间。"
Arthur C.Clark once suggested a revolutionary idea passes through three phases: 1. 'It's impossible--don't waste my time.'
第二阶段："这是可能的，但没有做的价值。"
2. 'It's possible, but not worth doing.'
第三阶段："我从一开始就说这是个好主意。"
3. 'I said it was a good idea all along.'
殖民火星这一想法——一个比月球遥远160倍的世界——将决定性地从第二阶段过渡到第三阶段，届时将有相当数量的人长期定居于太空之中。
The idea of colonising Mars--a world 160 times more distant than the Moon--will move decisively from the second phase to the third, when a significant number of people are living permanently in space.
火星对于那些有志前往的旅行者有着非同寻常的吸引力。
Mars has an extraordinary fascination for would-be voyagers.
美国、俄罗斯和欧洲充满了热情支持者——其中许多人是严肃认真的资深科学家，他们梦想着将人类送上火星。
America, Russia and Europe are filled with enthusiasts--many of them serious and senior scientists who dream of sending people to it.
他们的目标是可以理解的。
Their aim is understandable.
火星是太阳系中最像地球的那个星球。
It is the one world in the Solar System that is most like the Earth.
火星是一个拥有红色沙漠（因此得名"红色星球"）、万里无云的天空、猛烈沙尘暴、比大峡谷更宽阔的峡谷以及至少一座超过珠穆朗玛峰两倍之高的山峰的世界。
It is a world of red sandy deserts (hence its name--the Red Planet), cloudless skies, savage sandstorms, chasms wider than the Grand Canyon and at least one mountain more than twice as tall as Everest.
它看起来极适合人类定居。
It seems ideal for settlement.