(单词翻译:单击)
Someday, we're going to send people to Mars, and it's gonna be awesome.
总有一天，我们会把人送到火星上去，这将是很了不起的事情。
But for now, everyone from NASA to Elon Musk is still trying to figure out the best way to do it.
但现在，从宇航局到伊隆·马斯克(Elon Musk)，所有人都在努力想办法做到最好。
With today's rockets, a one-way trip to Mars takes somewhere around seven months,
如今的单程火箭到火星大约需要7个月，
but one company is developing an engine that might be able to get us there in only forty days.
但有一家公司正在开发一种引擎，可以在40天内把我们送到火星。
It's called the VASIMR engine, and it propels spacecraft using a jet of plasma.
它被称为VASIMR引擎，能利用等离子体喷射推动宇宙飞船。
VASIMR stands for Variable Specific Impulse Magnetoplasma Rocket,
VASIMR的意思是可变比脉冲磁等离子体火箭，
and the idea behind it has actually been around since the 1970s.
它背后的想法实际是从20世纪70年代开始的。
But engineers didn't make too much progress on it until 2015,
但直到2015年，工程师们才取得很大进展，
when NASA gave the Ad Astra Company a grant to develop it as part of their NextSTEP program.
美国宇航局给了阿斯特拉公司一笔拨款，作为NextSTEP项目的一部分来发展它。
It works using a kind of electric propulsion,
VASIMR使用一种电力推进装置工作，
and it's a big step up from the other engines available right now.
与现存的其他引擎相比是个巨大进步。
To get your rocket into space, you'd still need a chemical engine,
要想让火箭进入太空，你还需要一种化学发动机，
which generates thrust with a reaction that releases tons of gas, like combining hydrogen and oxygen.
它通过能释放大量气体的反应如氢氧结合产生推力。
So far, that's the only kind of engine we have that's powerful enough to get a heavy rocket to space.
到目前为止，这是唯一能让我们拥有足够强大力量的引擎，可以将重型火箭送入太空。
But once you're there, you can move it with all kinds of things,
但是一旦你到那里，就可以用各种各样的物体移动它，
from ions to particles of light, depending on what your mission is.
从离子到光粒子都可以，这取决于你的任务内容。
Right now, any spacecraft that would send people to Mars would still use a chemical engine,
现在，任何将人类送上火星的宇宙飞船仍在使用化学发动机，
because we mostly have the technology figured out.
因为大部分技术我们都已经解决了。
But carrying all that fuel also adds a lot of weight.
但是携带燃料也会增加很多重量。
So newer kinds of engines use electric propulsion, often in the form of ion thrusters,
所以新型发动机使用电力推进，通常是离子推进器推进，
which create a beam of charged atoms or ions to push your spacecraft around.
它能产生一束带电原子或离子来推动宇宙飞船。
Ion engines are a lot more efficient than chemical engines,
离子发动机比化学发动机效率高得多，
but they aren't designed to handle large payloads,
但它们并不是用来处理大载荷的，
like a bunch of humans and all the supplies they'd need for a trip to Mars.
比如一群人和他们到火星旅行的所有物资。
So we mostly use ion thrusters for small satellites.
于是我们主要把离子推进器用于小型卫星。
VASIMR also uses electric propulsion, but it will be way more powerful.
VASIMR也使用电力推进，但它将会更强大。
It propels the spacecraft by creating plasma, in the form of a super hot jet of ions and electrons.
它通过制造等离子体来推动宇宙飞船，采用超热离子和电子喷射的形式。
Unlike other kinds of electric propulsion, it uses radio waves to heat the plasma,
VASIMR不像其他电力推进装置，它利用无线电波加热等离子体，
rather than electrodes or other electronics in ion engines.
而不是离子发动机中的电极或其他电子设备加热。
Which among other things, makes the engine a lot more durable.
相比之下，这会使引擎更耐用。
To make the plasma, it starts by pumping a gas like hydrogen or argon into a tube,
为了制造等离子体，它首先将氢气或氩气之类的气体注入到一个管子中，
which is surrounded by a magnet and two couplers, a kind of device that emits radio waves.
并用一个磁铁和两个耦合器包围，形成无线电波发射装置。
Most kinds of gas will work, which makes VASIMR really versatile,
大多数种类的气体都可以，这使得VASIMR真正万能，
but hydrogen is a good choice if you want a lightweight, easy-to-find fuel.
但如果你想要一种轻便、容易找的燃料，氢是不错的选择。
Once the gas is pumped in, the first coupler strips some of the electrons off their atoms and turns the gas into plasma.
一旦气体被泵入，第一个耦合器将一些电子从原子中剥离出来，并将气体转化为等离子体。
At this point, it's already very hot, around 5500 degrees Celsius,
此时它已经非常热了，大约有5500摄氏度，
but then the second coupler makes it even hotter.
但是第二个耦合器使它更热。
It raises the plasma to 10 million degrees Celsius,
它将等离子体的温度提高到1000万摄氏度，
which isn't that far from the temperature inside the sun.
与太阳的温度相差无几。
A magnetic nozzle then turns that super hot plasma into a nice, controllable jet,
然后，一个磁喷嘴将超级热的等离子体变成漂亮的可控射流。
and it's shot out of the end of the engine.
从引擎末端射出。
Besides being more durable, VASIMR is great because it also has different settings,
除了更耐用，VASIMR的优秀还源于它有不同的设置，
like the gears on a car,
就像汽车上的齿轮，
which means it can generate the right amount of thrust for different kinds of missions.
这意味着它可以为不同任务产生合适的推力。
So besides getting people to Mars,
所以除了把人送去火星，
it could also be scaled down to send small satellites zooming around the Earth.
它也可以按比例缩小，发送围绕地球旋转的小型卫星。
But most importantly for our future astronauts,
但最重要的是，对于我们未来的宇航员来说，
VASIMR can be made big and powerful enough to move human-sized spacecraft.
VASIMR可以变大变强，足以推动人形大小的宇宙飞船。
Ion engines just aren't ready to do that yet,
离子引擎还没有准备好推动宇宙飞船，
partly because many tend to rely on more mechanical parts than VASIMR,
部分原因是许多人倾向于机械零件而不是VASIMR，
some of which aren't designed to work on a large scale.
有些设计并不是为了大规模载重。
Although engineers are working on that, too.
尽管工程师们也在致力于这个问题。
Still, there is one thing we need to figure out before VASIMR is ready to go: the power supply.
不过，在VASIMR准备就绪之前，还有一件事我们需要弄清楚:电力供应。
It takes a lot of power to produce all those radio waves,
产生无线电波需要很多能量，
especially if you want an engine strong enough to push a crew of astronauts.
特别是如果你想要一个足够强的发动机来推动一组宇航员。
Solar panels can generate enough power to propel small satellites,
太阳能电池板能产生足够多的能量驱动小型卫星，
but we'd need something a lot stronger for a full-sized spacecraft.
但是对于一艘全尺寸的宇宙飞船来说，我们需要更强的东西驱动。
And our best option is probably using a small nuclear reactor.
最好的选择可能是使用小型核反应堆。
But because those have the potential to be really dangerous,
但因为它可能非常危险，
we'll want to make sure that we're extra confident in that technology
我们要确保自己对这项技术有信心，
before we start using nuclear power to transport people through space.
之后才能开始使用核能运输人们穿越太空。
Right now, the goal for the VASIMR team is to develop an engine
现在，VASIMR团队的目标是开发一个引擎，
so it can fire for 100 consecutive hours at 100 kilowatts of power,
它可以在100千瓦的电力下连续燃烧100个小时，
which is 10 to 100 times more power than an ion thruster has.
比离子推进器的功率大10到100倍。
To get to Mars in 40 days, you'd still need a lot more power than that,
要在40天内到达火星，你需要比它更多的能量，
like, 2000 times more power.
比如2000倍的能量。
And that's probably where a nuclear reactor would come in.
这可能就是需要引入核反应堆的原因了。
But for now, 100 kilowatts is a good start.
但现在，100千瓦是个好的开始。
Ad Astra's plans with NASA are to have the engine ready for the 100 kilowatt goal by the summer of 2018.
阿斯特拉与宇航局的计划是在2018年夏天让发动机达到100千瓦的目标。
As of last August, they'd fired the engine for around 10 hours, so they're making progress.
截至去年8月，他们的引擎能够发动大约10个小时，所以他们在进步。
Still, even after they meet that goal,
即使VASIMR实现了这个目标后，
VASIMR will need to go through plenty of development and tests before we use it to go anywhere.
仍需要经过大量的开发和测试，才能使用它去任何地方。
So when the first human steps on Mars,
所以当人类第一次踏上火星的时候，
we'll probably have made it there with a chemical engine, since that technology is a lot more developed.
我们可能使用的是化学引擎，因为这项技术发展得很好。
But someday, our trips to Mars could be a whole lot faster.
但是有一天，我们去火星的旅程可能会更快。
Thanks for watching this episode of SciShow Space!
感谢您收看本期的太空科学秀！
If you thought getting to Mars in 40 days sounded cool,
如果你认为40天到达火星听起来很酷，
you can watch our episode on photonic propulsion,
可以观看我们电子推进的那期节目，
where we explain how we could someday get to Mars in only three days...at least in theory.
我们会为你解释仅用3天如何到达火星，至少理论上是这样。
But I wouldn't hold your breath.
但我不会让你感到意外。
