Floating in Space

Floating in Space

宇航员的太空生活

Jump up. jump as high as you can. You can't go very high, because Earth's gravity pulls you down. On Earth gravity is strong because Earth contains a lot of material-rocks and soil, water, and metals.

用力跳起来!能跳多高就跳多高。你无法跳很高,地球引力会把你拉回到地面。地球引力十分强大，因为地球是由许多物质组成的，包括岩石、土壤、水分和金属等。

If you were on the moon, you could jump much higher. The moon's gravity is much weaker than Earth's gravity. That's because the moon contains much less material. If you were on a shuttle or a space station, you could jump so high, you would float to the ceiling. Then you would float to the floor. Up you would float again; up and down, up and down. You would be floating in space. That's because gravity in a shuttle is very weak.

假如你在月球上,可以跳得更高。月球引力比地球引力弱得多,这是因为月球所含的物质比地球少得多。 如果你在航天飞机上,或在宇宙空间站里,你能跳得非常高,甚至能撞到天花板上,随后又飘回到地板上。 之后你会再次浮起来，再落下去,再浮起来,再落下去。你可以在空中飘浮着,因为太空引力很小。

In the shuttle there is so little gravity, it is often called zero gravity, There is no " down" or " up. " Astronauts do not jump inside a shuttle or a space station. They move very carefully. They hold on to straps with their hands or their feet. If they keep very still, astronauts can stay wherever they are, even without a strap. But if they lift an arm or a leg, they start moving. They might hit a ceiling or a wall, or they might spin around. Wherever they land, they can stand. That means they could stand on a wall or on the ceiling. Imagine how that would make you feel.

在航天飞机上引力太小了,我们称之为失重。在失重环境下,没有“上“下”方向之分。宇航员不能在航天飞机或空间站中乱跳,他们只能小心翼翼地行动,用手或脚抓住带子。如果保证完全静止，即使不抓住带子，他们也能够待在原地不动。但只要稍稍抬一下胳膊或腿他们就开始转动,也许会撞到天花板上、墙上,或在原地打转。无论在哪里落脚,他们都可以站住，也就是说可以站在墙上或天花板上。想象一下，那会是怎样一种感觉

Here on Earth astronauts are used to standing on the floor, just as you and I are. When they first find themselves standing on a wall many astronauts feel a bit dizzy. But after three or four days most astronauts get used to space, and they enjoy standing on a wall, or even a ceiling. In the shuttle or in a space station you don't feel any weight. You are weightless. Your weight on Earth is the amount of gravity pulling you down. If you weigh fifty pounds, the force of gravity on you is fifty pounds. The heavier you are, the greater the force of gravity on you. In the shuttle there is very little gravity, almost zero. So there is very little weight, close to zero. That's why it is easy to move. Also, it is easy to lift things, even if they would weigh a ton or more on Earth.

在地球上 ,宇航员就像你我一样 已经习惯了站在地板上 所以他们第一次站在墙上时会感到有点头晕目眩。但三四天后,大部分宇航员都能习惯太空的失重环境,甚至会很享受这种站在墙上、天花板上的感觉。 在航天飞机或空间站里,你感觉不到任何重量,因为你失重了!在地球上,你会受到地球吸引你向下的力量。你越重，受到的引力就越大。航天飞机上的引力几乎为零,所以体重也小到几乎为零。这就是为什么在航天飞机上行动感觉很容易,也能轻易举起重东西。即使是地球上重达一吨甚至更重的东西,你也能不费吹之力就举起来

It's really too easy to move around in the shuttle. You hardly need your muscles at all, and you hardly need your bones, But to stay healthy, each of us must use our muscles every day. Astronauts do this by using exercise machines. Even so, when astronauts stay in space very long, their muscles and bones get weaker. And astronauts grow one or two inches taller because gravity isn't pulling on them. When the astronauts return to Earth, they slowly become shorter again. These changes cause backaches for many astronauts. Since there is no " down" in space, water cannot flow. That means drinking is through a straw, And using the toilet is somewhat different. The astronaut is strapped to the toilet to keep from floating free. Urine is collected and vented into space. Solid waste is dried and stored until the shuttle lands. The toilet looks and works much like one on an airplane.

在航天飞机里，行动实在是太省力了,肌肉和骨骼几乎没有用武之地。为了保持健康宇航员需要做一些运动,每天使用健身器械来锻炼肌肉,即使是这样,如果他们在太空待的时间过长,肌肉和骨骼也会慢慢变虚弱。由于摆脱了引力的作用,宇航员的身高会增加 2-4厘米。当他们回到地球时，身高又会慢慢复。这种变化让许多宇航员患上了背痛。 因为太空没有上下之分，所以水是无法流动的。这意味着喝水需要吸管的帮助。此外使用马桶也有一点不同。为了防止身体到处漂浮,宇航员要用带子将自己固定在马桶上。小便被马桶收集后，排放到太空中。固体废物则被风干后储存好,由航天飞机带回地球处理。这种马桶的样子以及工作原理和民航飞机上的马桶很相似。