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NASA’s Parker Solar Probe is a mission to explore the Sun.
NASA的帕克太阳探测计划是一项探索太阳的任务
How can it do that? Why won’t the spacecraft melt?
它怎么做到的？探测器为什么没被熔化？
Excellent questions.
这是个好问题
You can’t face off with the sun without packing the right gear.
只有装配合适的装置才能对抗太阳的高温
This is why Solar Probe is equipped with a white shield
因此太阳探测器配备了一个白色防护罩
that reflects heat off the front and keeps things cool in the back.
来反射前方的热量 使后部保持较低的温度
The heat shield is made of a couple of different materials.
热能防护罩由几种不同材料制成
One is of carbon-carbon which is a lot like the graphite epoxy
其中一种是碳复合材料 很像石墨环氧树脂
you might see in your golf clubs or tennis rackets,
你可能在高尔夫球杆或网球拍上见过它
but it’s just been superheated.
但那些是热处理过的
The inside is a carbon foam
防护罩内部是泡沫碳
which is another form of carbon and is actually about 97% air.
它是另一种形式的碳 里面有97%的空气
It’s a very light weight way of making a very strong structure.
这是一种制作又轻又坚固的结构的方法
Nobody likes a needy explorer.
没人喜欢简陋繁琐的探测器
Solar Probe can take care of itself, thank you very much,
幸好帕克太阳探测器能照顾好自己
and that’s because it has autonomy software
因为它有智能自控软件
that will keep its instruments safe and cool behind the heat shield.
能让热能防护罩后的设备保持低温和安全
We are too far away to joystick it into place,
我们离它太远了 无法操纵防护罩改变位置
so it basically has to always be sensing whether
所以它基本上一直要自己监测
whether or not the heat shield is in the right position
热能防护罩是否在正确的位置上
and correct itself if it isn’t.
如果不是 就要自主调整
There are these things called solar limb sensors,
有一些名为太阳边缘传感器的东西
just poking out at the very edge of the shadow.
从阴影的边缘处探出
If those get illuminated,the spacecraft knows,
如果它们被照亮了 探测器就会知道
“Oh, I’m going the wrong direction,” and can actually right itself.
“哦 我正驶向错误的方向” 然后自我校正
It’s important to stay hydrated in the Sun, even for a spacecraft!
在阳光下补充水分很重要 对探测器来说也是一样！
Solar Probe circulates water to keep the solar cells from overheating.
太阳探测器通过水循环系统防止太阳能电池过热
It stays cool and keeps power.
电池会保持较低温度 储存好电量
Betsy: So basically water flows behind the solar arrays and into the radiators,
水会从太阳能电池板后面流过 然后流进散热器
so the water warms up when it’s behind the solar cells
所以水会在太阳能电池板后面升温
and then cools down at the radiator
然后在散热器里冷却下来
that heat transfer is happening a lot like the veins in your body
整个热传递过程很像你体内的血管传热过程
原因四 热量不是温度
Narrator: Yes, you read right: Heat is not the same as temperature.
是的 你没读错 热量和温度不一样
Temperature is a measurement, but heat is an energy transfer.
温度是一个测量结果 热量则是一种能量转换
This matters because Solar Probe
这很重要 因为太阳探测器
will be visiting the sun’s outer layer, the corona.
会到达太阳的外层 也就是日冕层
Like all stars, the Sun is made of plasma.
和所有恒星一样 太阳由等离子体构成
How tightly packed that plasma is depends on the layer.
等离子体的密度取决于它的层级
While the Sun’s corona has a very high temperature
尽管日冕的温度非常高
the plasma particles are fairly spread out,
但等离子体粒子相当分散
so even though the temperature in the corona is
所以即使日冕的温度高达
two to three million degrees Fahrenheit,
二百万至三百万华氏度
the heat around the spacecraft is manageable.
航天器附近的热量仍然是可控的
The corona and where we are going is actually not that dense at all,
日冕和我们要去的地方密度不高
there are only couple particles.
只有少量等离子体粒子
So we think about it,those are very hot,
我们能想到这些粒子温度非常高
but we are not touching a lot of them.
但我们不会和它们有太多接触
It’s kind of like when you put your hand into an oven.
这有点像你把手放到烤箱里
The oven might be at four five hundred degrees Fahrenheit,
这个烤箱也许有四五百华氏度
but your hand isn’t going to be at four five hundred degrees Fahrenheit.
但手的温度不会达到四五百华氏度
Thanks to its design and destination,
多亏了它的设计和稀疏的日冕层
this cool, confident spacecraft is all set to explore.
这个炫酷而自信的探测器已经准备好去探索太阳了
We can just sit back and chill,
当探测器接受高温炙烤时
as Parker Solar Probe takes the heat.
我们可以在凉爽的地方坐享其成
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