旅行者2号如何巧妙穿梭于浩瀚宇宙：英语精读讲义

This is the Voyager 2 space probe approaching Neptune,

这是正在接近海王星的 Voyager 2 太空探测器，

the furthest planet in our solar system.

也是我们太阳系中最遥远的行星。

It was the first time that any spacecraft had made the 4 billion kilometer journey, 語法

这是航天器首次完成这趟长达 40 亿公里的旅程，

and very little was known about this gas giant at the time.

当时人们对这颗气态巨行星知之甚少。

Neptune is so far away that it has only completed a single orbit of the Sun 語法

海王星距离我们如此之远，以至于它只绕太阳公转了一圈，

since we discovered it back in 1846.

自 1846 年被我们发现以来。

The true scale of our solar system is impossible for us to comprehend,

太阳系的真实规模对我们来说是无法想象的，

and due to the laws of physics,

而且受物理定律的限制，

navigating this huge expanse is anything but straightforward. 習語

在这片广袤的太空中航行绝非易事。

Nevertheless,

尽管如此，

in August 1977,

在 1977 年 8 月，

the Voyager 2 space probe began an incredible lifelong journey

Voyager 2 太空探测器开启了一段不可思议的终生旅程，

that would take it all the way through our solar system and beyond. 短語搭配

它将穿越整个太阳系并飞向更远的地方。

Today,

如今，

the space probe is some 20 billion kilometers from Earth,

这艘太空探测器距离地球约 200 亿公里，

but how did it get to this point? 表達脈絡

但它究竟是如何走到这一步的呢？

In this video,

在这段视频中，

we're going to look at the incredible physics behind Voyager 2's journey

我们将探讨 Voyager 2 旅程背后令人难以置信的物理学，

and the clever systems it used to navigate through space.

以及它用来在太空中导航的巧妙系统。

We'll also be giving away this awesome Saturn 5 framed print.

我们还将送出这幅精美的 Saturn 5 相框画。

So, stick around to the end of the video 短語動詞

所以，请看到视频最后，

to see how you could win.

了解你如何能够赢得奖品。

In the mid-60s,

在 60 年代中期，

a NASA engineer discovered a rare alignment of our four biggest planets was about to take place. 講解

一位 NASA 工程师发现我们四大行星即将发生罕见的连线现象。

This alignment only happened every 175 years,

这种连线每 175 年才发生一次，

and it would allow a spacecraft to visit all four of these giant planets in a single mission.

它能让航天器在一次任务中造访所有四颗巨行星。

And so,

因此，

it was up to Voyager 2 to take on this challenge. 講解

迎接这一挑战的重任就落在了 Voyager 2 肩上。

But in order to get there,

但为了到达那里，

Voyager 2 had to thread the needle through space, 習語

Voyager 2 必须在太空中精准穿梭，

perform four gravity assists,

完成四次引力弹弓，

and escape the Sun's gravity.

并逃离太阳的引力。

The planets in our solar system are constantly being pulled in by the Sun,

我们太阳系中的行星不断被太阳吸引，

but since they are also moving sideways very quickly,

但因为它们同时也在非常快地侧向运动，

their motion fights against the Sun's pull,

它们的运动对抗了太阳的引力，

keeping them in a constant orbit.

使它们保持在稳定的轨道上。

Without this velocity,

如果没有这种速度，

objects in space would simply be dragged straight into the Sun.

太空中的物体就会直接被拖入太阳中。

But if an object is traveling fast enough,

但如果物体的运动速度足够快，

it can outpace the Sun's pull,

它就能超越太阳的引力，

allowing it to completely break free and travel beyond our solar system. 短語動詞

从而完全挣脱束缚，飞出我们的太阳系。

And so,

因此，

Voyager 2 needed to go fast enough to escape the Sun's gravity.

Voyager 2 需要达到足够快的速度才能逃离太阳的引力。

The closer an object is to the Sun,

物体离太阳越近，

the more it will get pulled in.

它受到的引力就越大。

The Sun's gravity creates a deep well in the fabric of space,

太阳的引力在空间结构中产生了一个深井，

which we can essentially think of as a hill. 短語搭配

我们可以把它看作是一座山。

An object trying to escape from the bottom of the hill

一个试图从山底逃离的物体，

will need much more velocity than one escaping from the top.

需要比从山顶逃离的物体大得多的速度。

Since Earth is still relatively close to the Sun,

由于地球相对来说仍然靠近太阳，

Voyager needed a lot of energy to escape.

Voyager 需要大量的能量才能逃逸。

None of the rockets around at the time were powerful enough to do this.

当时没有任何火箭足够强大来实现这一点。

But due to this incredible alignment,

但得益于这种不可思议的连线现象，

Voyager could use gravity assists to slingshot itself from planet to planet, 用詞

Voyager 可以利用引力弹弓将自己从一颗行星甩向另一颗行星，

increasing its speed along the way.

并在途中不断提高速度。

In order to receive a gravity assist,

为了获得引力弹弓，

it used these giant magnets.

它使用了这些巨大的磁铁。

Just kidding.

开玩笑啦。

But these magnets were used to hang up these awesome metal posters from Displate.

不过这些磁铁是用来挂 Displate 出品的这些超棒金属海报的。

Displates are designed to last with their sturdy, magnet-mounted, and durable build.

Displate 坚固耐用、采用磁吸安装，旨在长期陪伴。

They're customizable, collectible, and easy to adjust,

它们可以定制、收藏并且易于调整，

so you can experiment with different arrangements as often as you'd like.

所以你可以随心所欲地尝试不同的排列方式。

With just 20 seconds of setup time,

只需 20 秒的安装时间，

Displates can be mounted without power tools or damage to your walls.

Displate 就可以免工具安装，也不会损坏墙壁。

Whether you're in the market for James Webb artwork, 習語

无论你是想寻找 James Webb 的艺术作品，

Voyager artwork,

还是 Voyager 的艺术海报，

or my current favorite,

或者我目前最喜欢的，

the Grand Tour from the official NASA collection,

NASA 官方系列中的 Grand Tour，

you're sure to find a design that speaks to you. 習語

你肯定能找到符合心意的设计。

So, why not add a touch of interstellar flair to your home or office with Displate.

所以，为什么不用 Displate 为你的家或办公室增添一丝星际风情呢？

Visit the link in the description to start your collection today

请点击描述中的链接，今天就开始你的收藏，

and get up to 37% off.

并享受最高 37% 的折扣。

In order for Voyager to leave our solar system,

为了让 Voyager 离开我们的太阳系，

it had to exceed the Sun's escape velocity,

它必须超过太阳的逃逸速度，

which at the distance of Earth was about 42 km/s.

在地球的距离上大约是 42 公里/秒。

Despite launching on the most powerful rocket around at the time, 語法

尽管使用了当时最强大的火箭发射，

it could only provide a delta V of around 10 km/s.

它也只能提供大约 10 公里/秒的 delta V。

This may not sound like a lot,

这听起来可能不算多，

but Earth was already moving around the Sun at 30 km/s.

但地球已经在以 30 公里/秒的速度绕太阳运行。

So, by launching Voyager in the direction of Earth's travel,

因此，通过顺着地球的运行方向发射 Voyager，

it took advantage of this velocity, 短語搭配

它利用了这一速度，

allowing it to reach around 40 km/s relative to the Sun.

使其相对于太阳的速度达到了约 40 公里/秒。

This was enough to escape Earth's gravity and place it into a very large orbit around the Sun,

这足以摆脱地球的引力，并将其送入一个围绕太阳的巨大轨道，

one that would take it well past the distance of Mars.

这个轨道将把它带到远超火星距离的地方。

Under normal circumstances, 短語搭配

在正常情况下，

it would remain in this orbit indefinitely.

它将无限期地留在这个轨道上。

But since it was trying to get a gravity assist from Jupiter,

但由于它试图从木星获得引力弹弓，

it aimed itself at the point where Jupiter was going to be by the time it arrived. 語法

它瞄准了它到达时木星将会出现的位置。

However,

然而，

despite the sheer scale of the area around Jupiter,

尽管木星周围的区域极其广阔，

Voyager had to thread itself through a very narrow 150 km wide corridor

Voyager 还是得精准穿过一条只有 150 公里宽的极其狭窄的通道，

and arrive at a specific point to the nearest second, 短語搭配

并精确到秒到达特定位置，

all whilst traveling at 10 km/s.

同时其飞行速度高达 10 公里/秒。

If Voyager missed this point or was a few seconds off,

如果 Voyager 错过了这个点或偏差了几秒钟，

it would have ruined the gravity assist and its following gravity assist around Saturn.

就会破坏这次引力弹弓及其随后在土星的引力弹弓。

In order to achieve such incredible accuracy,

为了实现如此惊人的准确度，

Voyager had to know its exact location in space and control its speed with great precision.

Voyager 必须知道它在太空中的确切位置，并精确控制其速度。

Five sets of thrusters placed around the space probe would allow Voyager to rotate around all three of its axes.

安装在太空探测器周围的五组推进器可以让 Voyager 围绕其三个轴旋转。

This was super important since its large antenna had to be constantly facing Earth

这超级重要，因为它的大天线必须不断朝向地球，

in order to send and receive signals.

以便发送和接收信号。

These thrusters would fire tiny millisecond pulses,

这些推进器会进行毫秒级的短促脉冲点火，

rotating Voyager at around 0.3 degrees a second.

以每秒约 0.3 度的速度旋转 Voyager。

At this rate, 短語搭配

按照这个速度，

it would take an entire 5 minutes just to turn 90 degrees.

仅仅转动 90 度就需要整整 5 分钟。

Then,

另外，

there was another set of identical thrusters that could be fired for longer durations

还有一组相同的推进器可以较长时间地启动，

to alter Voyager's speed,

用来改变 Voyager 的速度，

allowing NASA to finely control its trajectory over time.

从而让 NASA 能够随着时间的推移精细控制其轨迹。

But how did Voyager actually know where it was and where it was going?

但 Voyager 究竟是如何知道自己在哪以及要去哪的呢？

Located on Voyager's antenna was a device called a Sun sensor.

在 Voyager 的天线上有一个被称为太阳传感器的设备。

It detected the Sun as the brightest object in space

它将太阳探测为太空中最亮的物体，

and commanded Voyager to rotate until it locked onto it. 短語動詞

并指挥 Voyager 旋转，直到锁定太阳。

This would correctly align the x and y axes and ensure that Voyager's antenna was facing Earth.

这将正确对齐 x 轴和 y 轴，并确保 Voyager 的天线朝向地球。

In order to sort out the roll axis, 短語動詞

为了解决滚转轴的问题，

a star tracker facing 90 degrees away from the Sun sensor

一个偏离太阳传感器 90 度的星敏感器

would look for a specific star which had a known level of brightness.

会寻找具有已知亮度级别的特定恒星。

Again,

同样，

Voyager would rotate around this axis until it locked onto the star.

Voyager 会绕这个轴旋转，直到锁定那颗恒星。

But Voyager couldn't always rely on these systems. 短語搭配

但 Voyager 不能总是依赖这些系统。

Anytime Voyager passed by a planet, 語法

每当 Voyager 经过一颗行星时，

its Sun sensor would be temporarily blocked.

它的太阳传感器就会被暂时遮挡。

Likewise,

同样，

when Voyager rotated to take pictures of specific targets,

当 Voyager 旋转以拍摄特定目标的照片时，

both sensors would no longer be facing their reference points.

这两个传感器就不再朝向它们的参考点了。

And so,

因此，

to keep track of how much Voyager had rotated, 短語搭配

为了追踪 Voyager 旋转了多少度，

it had an onboard gyroscope,

它配备了机载陀螺仪，

which could be used for several hours at a time. 短語搭配

每次可以使用几个小时。

This was a disc mounted on a three-axis gimbal.

这是一个安装在三轴万向节上的圆盘。

When activated, 語法

启动后，

the disc would spin and its angular momentum would keep it perfectly stable.

圆盘会旋转，其角动量将使其保持完美稳定。

As Voyager rotated,

当 Voyager 旋转时，

the gimbals would rotate around this disc and a device would measure how much its orientation had changed.

万向节会围绕这个圆盘旋转，一个设备会测量其方向改变了多少。

Voyager then knew exactly how much it had to rotate in order to return to its Earth-facing position.

然后 Voyager 就能准确知道自己需要旋转多少度才能恢复面向地球的位置。

This entire system worked very well and gave Voyager a fixed orientation in space.

这整个系统运作得非常出色，赋予了 Voyager 在太空中的固定方位。

But knowing the orientation was only part of the problem. 表達脈絡

但知道方位只是问题的一部分。

In order to plot its trajectory,

为了绘制其轨迹，

NASA needed to know how fast it was going.

NASA 需要知道它飞得有多快。

They did this by sending a signal out to Voyager 語法

他们通过向Voyager发送信号，

and timing how quickly it would respond.

并测量它多快作出响应，来做到这一点。

Since each signal traveled at the speed of light,

由于每个信号都以光速传播，

multiplying these two numbers would give them Voyager's distance.

将这两个数字相乘就能得出 Voyager 的距离。

Then,

然后，

they'd send another signal,

他们会再发送一个信号，

which would give them Voyager's new distance.

从而得出 Voyager 的新距离。

By subtracting these distances,

通过计算这两个距离的差值，

they could figure out how much Voyager had traveled in that time. 短語動詞

他们可以算出在这段时间内 Voyager 飞行了多远。

With this,

有了这个数据，

a simple calculation would tell them how fast Voyager was traveling.

一个简单的计算就能告诉他们 Voyager 的飞行速度。

With all of these data points,

利用所有这些数据点，

NASA could continuously plot Voyager's trajectory and see how it compared to the desired trajectory.

NASA 能够持续绘制 Voyager 的轨迹并将其与预期轨迹进行对比。

If the space probe was a bit off,

如果太空探测器有点偏离轨道，

they could send a command to Voyager,

他们就会向 Voyager 发送指令，

which would fire up its thrusters to fix it. 短語動詞

启动它的推进器来进行修正。

With this incredible system,

凭借这个不可思议的系统，

Voyager arrived at its Jupiter target point

Voyager 到达其木星目标点时

just 1.4 seconds late and only 60 km off course. 短語搭配

仅迟到了 1.4 秒，偏离航线仅 60 公里。

As Voyager 2 approached Jupiter,

随着 Voyager 2 接近木星，

its speed had slowed considerably to around 10 km/s as it reached the top of its orbit.

当它到达轨道顶端时，它的速度大幅减慢到了大约 10 公里/秒。

This was now well below the Sun's escape velocity,

现在这远低于太阳的逃逸速度，

which at Jupiter's distance was around 18 km/s.

在木星的距离上，该逃逸速度约为 18 公里/秒。

But as it got closer to Jupiter,

但随着它越来越靠近木星，

its gravitational pull started to have an effect on the space probe. 短語搭配

木星的引力开始对这艘太空探测器产生影响。

Since Jupiter was already moving very fast in this direction,

由于木星已经朝着这个方向高速运动，

it pulled Voyager in

它把 Voyager 拉了过来，

and essentially multiplied its current speed with Jupiter's speed,

并实质上将 Voyager 当前的速度与木星的速度叠加，

sending it off at an even greater velocity.

从而以更快的速度将其甩出。

Voyager was now going faster than the Sun's escape velocity,

此时 Voyager 的速度已经超过了太阳的逃逸速度，

and from this point onwards, 表達脈絡

从此刻起，

it was destined to escape the solar system. 語法

它注定要飞出太阳系。

But the journey wasn't over yet. 表達脈絡

但旅程还没有结束。

Voyager went on to complete two more gravity assists around Saturn and Uranus, 短語動詞

Voyager 后来又在土星和天王星周围完成了两次引力弹弓，

making incredible discoveries along the way. 習語

并在沿途取得了惊人的发现。

The final gravity assist would be around Neptune,

最后一次引力弹弓将发生在海王星周围，

but this gravity assist would go a little bit differently. 短語搭配

但这次引力弹弓的过程会有点不同。

Since there were no more planets to visit after Neptune,

因为在海王星之后没有其他行星可以造访，

Voyager didn't have to follow any particular path around Neptune.

Voyager 不需要遵循围绕海王星的任何特定路径。

However, scientists were very interested in flying as close as possible to Triton, 語法

然而，科学家们非常希望能尽可能靠近 Triton 飞行，

one of Neptune's moons.

它是海王星的一颗卫星。

But Triton orbits at a steep angle,

但 Triton 的轨道倾角很大，

and so getting close would require a dramatic change of direction.

所以要接近它就需要剧烈改变方向。

And so,

因此，

instead of approaching from behind Neptune, 語法

Voyager 没有从海王星后面接近，

Voyager approached just a tiny bit in front,

而是稍微靠前了一点接近，

heading over the planet's North Pole.

从这颗行星的北极上空飞过。

This was enough to bend Voyager's trajectory downwards

这足以使 Voyager 的轨迹向下弯曲，

whilst also slowing it down. 短語動詞

同时也减慢了它的速度。

5 hours later,

5 个小时后，

Voyager flew past Triton.

Voyager 飞越了 Triton。

And from then on,

从那时起，

began its lifelong journey into deep space.

开始了它深入外太空的终生旅程。

This epic journey took 12 years in total,

这段史诗般的旅程总共历时 12 年，

and the discoveries that Voyager made along the way

而 Voyager 沿途的发现

taught us an incredible amount about our solar system. 短語搭配

让我们对太阳系有了难以置信的丰富了解。

And now,

现在，

for the moment you've all been waiting for, 表達脈絡

到了大家期待已久的时刻，

the winner of this awesome Falcon 9 framed print is Matthew Cole.

这幅精美 Falcon 9 相框画的获胜者是 Matthew Cole。

Congratulations.

恭喜你。

Sorry if you didn't win,

如果没中奖也不用遗憾，

but in the next video,

但在下一个视频中，

you'll get another chance.

你会得到另一次机会。

Next time,

下一次，

we'll be giving away this epic Saturn V framed print.

我们将送出这幅史诗般的 Saturn V 相框画。

All you need to do is sign up at the link below 語法

你只需在下方链接中注册，

and leave a comment saying what you think will happen during Starship's first test flight. 語法

并留下评论，说说你认为在 Starship 的首次测试飞行中会发生什么。

Thank you very much for watching,

非常感谢大家的观看，

and I'll see you in the next video.

我们下个视频再见。