为什么在降落到月球后,进行舱外活动时宇航员一定要关闭LM的舱门?Why did they bother closing the hatch on the LM while doing EVA?

【翻译自Quora】

@ Mark Shulmann, Life-long student of the Apollo Program 的回答

Yes, they did actually go to the effort of closing the LM hatch. This was actually news to me. Before I started researching this answer, I figured: close it / leave it open — didn’t matter. But then I found this in the Apollo 15 flight plan:

是的,他们确实想要关闭LM舱口。 这实际上对我来说是个新消息。 在开始研究此答案之前,我想过:关闭或者保持打开状态应该都没关系。 但是后来我在阿波罗15号的飞行计划中发现了这一点:

There it is, actually on the checklist: the Lunar Module Pilot (Jim Irwin on Apollo 15) is supposed to close the hatch on the way out. Since nothing goes on the checklist without a reason, there must be a reason.

实际上,它在计划清单上:“登月舱飞行员”(阿波罗15号上的吉姆·欧文)应该在出行时关闭舱口。 虽然检查清单上没有任何原因,因此一定是有原因的。

On Apollo 12, Al Bean even announced it:

在阿波罗12号,艾尔·宾恩(Al Bean)甚至宣布了这一点:

115:50:12 Bean: Okay; I’m pulling the hatch closed here.

115:50:12 Bean:好的; 我要在这里关闭舱门。

It can’t be that they’re worried about stuff blowing into or out of the cabin — with no air on the moon, that’s not a concern. So the reason? Turns out it’s heat. So much of the challenge of spaceflight involves controlling heat, something that’s relatively simple on Earth but much more difficult in space. This is the perfect example. Al Bean explained after the mission:

他们并不是担心东西会飞进或飞出机舱-月球上没有空气,这不是问题。 那么原因呢? 原来是热。 太空飞行面临的许多挑战都涉及控制热量,这在地球上相对简单,但在太空中则要困难得多。 这是一个完美的例子。 艾尔·比恩(Al Bean)在任务结束后解释说:

“We closed the door for thermal reasons. They didn’t want the temperatures in the LM affected by looking at either the dirt or the sky. You’re getting all that radiant stuff going on in that vacuum. You have to be careful.”

“我们因为热的原因关闭了门。他们不希望在他们观察尘土或天空的时候,LM的温度被影响了。在真空中,所有正在散发出来的辐射都在不断散发。您必须小心。 ”

The idea, of course, was not to latch it closed — just to pull it closed enough that the hatch blocked radiant heat.

当然,这个想法不是要完全关门,而是要把它关到足够的程度,以使舱口挡住辐射热。

By the way, the Apollo 11 astronauts joked about accidentally locking the hatch, but in fact this wasn’t possible. The hatch latching mechanism could be operated from either inside or outside, and if any pressure accumulated inside the LM while the hatch was closed, the cabin vent could be activated from either side as well.

顺便说一句,阿波罗11号的宇航员开玩笑说意外锁上了舱门,但实际上这是不可能的。 舱门闩锁机构可以从内部或外部进行操作,如果在舱门关闭时LM内部积累了任何压力,那么也可以从任一侧机舱通风口进去。

This was a fascinating question for me! The OP (Jared Anwyl) thought to ask a question that I’d never considered before, and that led me to learn something new. This is why I love Quora!

这对我来说是一个有趣的问题! OP(Jared Anwyl)想问一个我以前从未考虑过的问题,这使我学到了一些新东西。 这就是为什么我爱Quora!

【评论区】

@ Rogerio Penna

“ So much of the challenge of spaceflight involves controlling heat, something that’s relatively simple on Earth but much more difficult in space.”

Does not seem so after I leave my car on the parking lot from 9am to 15pm of a 40º C summer day…

“太空飞行面临的诸多挑战都涉及控制热量,这在地球上相对简单,但在太空中要困难得多。”

如果你在夏季40ºC的上午9点至下午15点将汽车停在停车场后,你会发现情况似乎并非如此……

@Tom Quetchenbach

I know this is a joke, but it actually leads to a decent comparison of how hard it is to cool things in space. A typical car air conditioner has a capacity of maybe 10–15 kW or more. The radiator to cool a single PV array on the ISS has a similar capacity (15 kW), but to accomplish that in space it has a surface area of 42 square meters and weighs 740 kg, which is probably about half the weight of your entire car. That’s just the radiator itself, not including the other parts of the cooling system. (https://www.nasa.gov/pdf/473486m…)

我知道这是个玩笑,但这实际上却是讨论在太空中如何冷却的一个不错的比较。 典型的汽车空调可能为10–15 kW或更高。 用于冷却ISS上单个PV阵列的散热器具有类似的容量(15 kW),但是要实现这一点,在空间上它的表面积为42平方米,重740千克,可能大约是你的整个汽车的一半——而且那还只是散热器本身,不包括冷却系统的其他部分。 (https://www.nasa.gov/pdf/473486m …)

(That’s because the condenser in the car AC is air-cooled. In space, there is no air to take away the heat, so it all has to be removed by radiation. Even though radiators on earth are called “radiators” they really work mostly by convection.)

(这是因为汽车空调中的冷凝器是风冷的。在太空中,没有空气带走热量,因此所有热量都必须通过 radiation 除去。地球上的 radiation 被称为“散热器”,它们也确实可以工作。 主要是通过对流。)

Or, if your car doesn’t have AC, you can roll down the windows, which is not recommended in space.

或者,如果您的汽车没有空调,则可以将窗户卷下来,但不建议在太空中使用。

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