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There's been all kinds of buzz lately about some new space tech that could send a spacecraft to Mars in three days
最近各种太空新技术的消息甚嚣尘上，其中包括三天内把宇宙飞船送到火星，
and maybe even get spaceships to exoplanets that are light-years away,
甚至可能会让宇宙飞船飞到光年远的系外行星上，
which kind of sounds like something out of a science fiction novel,
这听起来有点儿像科幻小说的内容，
but a group of researchers from the University of California-Santa Barbara is working on a new way to travel in space.
但加州大学圣巴巴拉分校的一组研究人员正在研究太空旅行的新方式。
Known as photonic propulsion, it would use a giant set of lasers to push ships along,
它被称为光子推进，使用一套巨大的激光器来推动飞船前进，
and if it works, it could eventually be used to explore other star systems.
如果奏效的话，它最终可用于探索其他恒星系。
But that's a big if.
但这是一个很大的未知数。
The project is called DEEP-IN,
这个项目叫DEEP-IN，
and its goal is to use electromagnetic acceleration to get ships close-ish to the speed of light,
它的目标是利用电磁加速使飞船速度接近光速，
fast enough that interstellar travel could actually make sense.
快到能够做星际旅行。
These days, our spaceships use chemical acceleration, in other words, they burn fuel, and they are fast.
现在，我们的飞船使用的是化学加速，也就是说，它们用燃料加速。
They're just not fast enough to travel to other stars in any reasonable amount of time,
在合理的时间内，它们的速度不足以穿行到其他恒星上，
which is where electromagnetic acceleration comes in.
这就是电磁加速的用处了。
Instead of using chemical energy to push itself forward,
它不是使用化学能量推动自己前进的，
a DEEP-IN spacecraft would use the energy from electromagnetic radiation,
DEEP-IN的飞船将利用电磁辐射的能量，
more specifically, the energy from a huge set of lasers powered by sunlight.
再具体点说，它的能量来自一套由阳光驱动的激光器。
That laser array technology is a whole project all by itself
激光器阵列技术本身就是一个完整工程，
called the Directed Energy System for Targeting of Asteroids and Exploration, or DE-STAR,
被称为靶向小行星及勘探的定向能量系统（DE-STAR），
and being developed by the same team of researchers,
它是由同一组研究人员开发的，
and as you might have noticed from the first part of that acronym,
你们可能已经由首字母缩略词的开头部分注意到，
DE-STAR would be a laser system with multiple uses, like destructive uses.
DE-STAR是具有多种用途的激光系统，比如破坏作用。
DE-STAR is mainly being designed to protect Earth,
它的设计主要是为了保护地球，
both by diverting asteroids that are heading for us, and by vaporizing space debris.
方法是改变朝我们飞来的小行星轨迹和蒸发空间碎片。
This photon-driven propulsion thing is just a bonus, and a pretty huge one.
这种光子驱动的推进装置只是一个额外奖励，而且是一个相当大的奖励。
It's based on the idea that light has a lot of pushing power, which comes from its momentum.
它基于光因动量有很大推力的原理。
We might not feel that push from just walking around on Earth,
我们在地球上行走时可能感受不到光的推力，
but a giant reflector screen in space does feel it.
但太空中的巨大反射屏能感觉到它。
That's the science behind solar sails, and we've already built spaceships that use them.
这就是太阳帆背后的科学，我们已经在利用它们建造飞船了。
When the photons in light bump into a solar sail, their momentum is transferred,
当光子撞上太阳帆时，它们的动量被转移，
and the spacecraft is propelled forward a little bit.
宇宙飞船会向前推进一点儿。
DE-STAR's lasers would provide lots of light that we could use to take the solar sails concept one step further
DE-STAR的激光会为我们提供大量的可用光，我们可以把太阳帆的概念更进一步，
and start building spacecraft that use laser sails.
并开始建造使用激光帆的航天器。
See, solar sails are limited, because the light coming from the sun only comes with so many photons,
太阳帆有限，因为来自太阳的光子只有这么多，
but this laser sail will have concentrated beam of photons shooting directly at it.
但是这种激光帆将会集中光子束直接射向它。
It's the difference between a sprinkler and a fire hydrant.
这是洒水车和消防栓的区别。
When it gets hit by that laser beam,
当它被激光束击中时，
the laser sail and anything that happens to be attached to it, like a spaceship,
激光帆或任何附属在它上面的物体比如飞船，
is going to start zooming through space.
都会开始在太空中加速。
A ship using a laser sail wouldn't have to carry as much fuel,
使用激光帆的飞船不需要携带很多燃料，
which would mean that it could have a much lower mass.
意味着它的重量会减少很多。
It could also, in theory, go very, very fast.
理论上来讲，它的速度会非常非常得快。
With a huge laser array putting out 50-70 gigawatts of power,
依靠巨大激光阵列输出50-70吉瓦的电力，
a 100 kilogram ship about the size of Voyager 1 could travel at around 1.5% of the speed of light,
一艘“旅行者1”号大小、100公斤重的飞船，它的速度能达到光速的1.5%，
nearly 300 times Voyager's top speed.
几乎是它最高速度的300倍。
But, not surprisingly, there are still challenges to solve when it comes to making spaceships powered by giant lasers.
但不要惊讶，用巨大激光器驱动的飞船仍面临很多挑战。
We could send a smaller probe to Mars in three days,
我们可以三天向火星发射一枚小型探测器，
or a larger craft on a trip that would take about a month,
或一个月发射一个大型航天器，
but we'd need a giant square laser array that's 10 kilometers long on each side,
但我们需要一个边长10公里的巨大正方形激光阵，
which presents some obvious problems.
这就出现明显的问题了。
Getting stuff to space is expensive, let alone 100 square kilometers' worth of high-powered laser equipment.
把东西送入太空代价巨大，更不用说100平方公里的高性能激光设备了。
And even if we did get everything to the right spot, it would be incredibly difficult to assemble.
即使我们把所有东西都弄到合适的地方，组装起来也很难。
And even if we did get everything to the right spot, it would be incredibly difficult to assemble.
即使我们把所有东西都弄到合适的地方，组装起来也很难。
Building a laser sail for this super fast trip to Mars would also be tough.
为超速火星之旅建造激光帆也很困难。
According to researchers, it would have to be only a micron thick, that's a thousandth of a millimeter.
据研究人员称，它只能是一微米厚，即千分之一毫米。
But to work properly, that whisper thin laser sail would have to weigh about as much as the spaceship itself.
但要想正常工作，薄激光帆必须和飞船本身一样重。
Meaning that it would have to be a huge thin sail,
这意味着它必须是巨大的薄帆，
but strong enough to be stable while the ship is moving ridiculously fast,
而且在飞船快速移动中还要足够坚固，能保持稳定，
and we also have no idea how to slow the spacecraft down once it gets to wherever it's going.
同时我们也不知道航天器一旦到达目的地该如何降速。
So if we're talking about sending ships to Mars in three days,
所以如果我们要说三天内发送飞船到火星的话，
we're probably getting ahead of ourselves a little bit here.
可能有点儿超前了。
Really, the first step to making this research a reality is building a much smaller set of lasers.
事实上，这个研究的第一步是建立一套更小的激光器。
The team's plan, assuming NASA chooses to move forward with their idea,
假设宇航局选择推进他们的想法，该组研究人员的计划是
is to start with a laser array that's only one meter square,
从建立一个边长为一米的激光阵开始，
and then we just keep building bigger sets of lasers,
随后继续建造更大的激光器，
'til we eventually figure out how to build one that's ten kilometers on a side,
直到我们最终弄清楚如何建造边长10公里的激光器，
then we can use that to launch what are known as wafer sats.
然后我们可以用它来发射所谓的微晶卫星。
These miniature spacecraft would weigh no more than a gram,
这种微型宇宙飞船的重量不超过一克，
but they'd have sensors, a power source, teeny tiny thrusters, and communications equipment.
但它们有传感器、电源、微小的推进器和通讯设备。
That giant set of lasers could accelerate those wafer sats to about 25% of the speed of light,
这套巨大的激光器可以使微晶卫星达到光速的25%大小，
sending them light-years away, where they could tell us about interstellar space and exoplanets.
可以把它们送到光年远的地方，那里有星际空间和系外行星的信息。
They might even be able to reach the nearby star system, Alpha Centauri only 15 years after they launch.
它们甚至可以在发射15年后到达附近的恒星系——半人马座的阿尔法星。
So there's still a huge amount of research, technology development, and testing needed
所以还需要大量的研究、技术研发和测试
before we can use lasers to propel any sort of spacecraft, even a little wafer one,
然后才能利用激光器推进任何种类的航天器甚至是微晶卫星，
and it's going to be a very long time before we're zooming over to Mars in just a few days,
在我们能几天飞到火星之前仍需要很长时间，
but it probably is possible.
但是有可能的。
Thanks for watching this episode of SciShow Space,
感谢您收看本期的太空科学秀，
and thanks especially to our Patrons on Patreon, who help make this show possible.
特别感谢Patreon的大力支持。
If you want to help us keep making episodes like this,just go to patreon.com/scishow
如果你想我们继续制作此类节目，就登录patreon.com/scishow吧，
and don't forget to go to youtube.com/scishowspace and subscribe.
也不要忘了登录youtube.com/scishowspace点击订阅哦！
