C Stuart Hardwick有关航天的回答收集(二)

有什么我们如今正在使用的NASA的发明吗?What are some of the NASA inventions we use today?

  • Aerodynamic truck fairings — originally developed at NASA Ames Research Center, which cut 25% off the fuel cost of long-haul truckers.
  • 气动卡车整流罩-最初由NASA艾姆斯研究中心开发,可将长途卡车司机的燃料成本降低25%。
  • The CMOS image sensor used on almost all inexpensive consumer digital cameras—originally developed at NASA Jet Propulsion Labs to provide better quality imaging from spacecraft.
  • CMOS图像传感器,几乎用在所有廉价的家用数码相机上,这些相机最初是由NASA喷气推进实验室开发的,目的是从航天器提供更好的成像质量。
  • Grooved pavement — developed by NASA Langley Research Center’s Safety Grooving research program to reduce the hydroplaning on aircraft on runways, and later expanded to all concrete highways. State of California research confirms grooved pavement cuts loss of control incidents by 98%, and other research has found it also reduced highway noise in certain applications.
  • 开槽路面-由NASA兰利研究中心的“安全开槽”研究计划开发,旨在减少飞机在跑道上的滑水现象,后来扩展到所有混凝土高速公路。 加利福尼亚州的研究证实,开槽的路面可将控制事件的损失减少98%,其他研究发现,它还可以减少某些情况下中的公路噪音。

Is the proper saying “Houston, we have a problem” or “Houston, we’ve had a problem”?

Neither.

What Jim Lovell actually said during the mission was “Houston, we’ve had a problem.” This was after CAPCOM asked “Say again?” after Jack Swigert reported, “I believe we’ve had a problem here. “

Jim Lovell在执行任务期间实际上说的是“ Houston, we’ve had a problem. ”在 Jack Swigert 报告说“ I believe we’ve had a problem here ”,CAPCOM要求杰克·斯维格特(Jack Swigert)“再说一次?”, 然后Jim Lovell 说出了那句话。

In the movie Lovell says “Houston, we have a problem,” probably because the screenwriter thought that phrasing was ever so slightly more dramatic and in the moment—as I would have. That’s a pretty standard sort of detail we all learn to look for in revision.

洛弗尔在电影中说“ Houston, we have a problem ”,可能是因为编剧认为现在和现在一样,措辞更加生动。 这是我们大家都希望在修订中寻找的相当标准的细节。

Neither is more “proper.” Both are perfectly good English. One is what was said in real life, and one is what was said in a very fine movie.

两者都是“合适的”。两者都是完美的英语。 一个是真实发生过的,一个是一部非常棒的电影中所说的。

航天飞机是如何固定在发射架上的?How was the space shuttle attached to the launch gantry?

By eight large bolts with frangible (explosively separable) nuts.

通过八个带易碎(方便爆炸脱离)螺母的大螺栓。

Four bolts held down each solid rocket booster. The ET and the orbiter hung from the SRBs.

每个固体火箭助推器压下四个螺栓。 ET和轨道器悬挂在SRB上。

That might not seem like much, but remember that essentially, these bolts only needed to protect the stack from shifting in the wind, and it was never exposed to much wind, and it was loaded with trainloads worth of propellant. It’s not like it was going to wander off.

看起来似乎并不多,但请记住最关键的是,这些螺栓仅需要保护航天组件免受一般风的影响,组件是永远不会暴露在大风中的,并且装有大量的推进剂,更加难以被风影响。

There is a delicate balance to such things. If the SRBs (or any other part of the system) were really securly bolted down and the release mechanism failed, the result would be the destruction of the whole stack and the launchpad.

这些事情之间有着微妙的平衡。 如果SRB(或系统的任何其他部分)确实被安全固定,但发射时失败,那么结果将是整个组件和发射台的破坏。

But in fact, on at least one occasion that’s I’m aware of, two of the eight bolts failed to separate, and the force of the launch just tore through them, causing only minor damage to the SRB skirt.

但实际上,至少在我知道的一种情况下,如果八个螺栓中的两个未能分离,发射力刚好拉断了它们,仅对SRB裙板造成了很小的损坏。

用于Mercury-Atlas和Mercury-Redstone火箭的发射逃生塔顶部的小型狭窄结构的目的是什么? 小结构的顶部有一个小锥。 What was the purpose of the small narrow structure on top of the launch escape tower used for Mercury-Atlas & Mercury-Redstone rockets? The small structure has a little cone on top of it.

An aerodynamic spike.

气动学长钉。

The spike served exactly the opposite purpose during ascent as the blunt heat shield did during descent—it created a shockwave around the escape motor assembly, serving the same purpose as an aerodynamic nose cone but at much lower weight. The concept was used on a number of early ballistic missiles, and deployable aerospikes have sometimes been used to make missiles more compact.

上升过程中,尖峰的作用与下降时钝式隔热罩的作用恰好相反—它在逃逸马达组件周围产生了冲击波,其作用与气动鼻锥相同,但重量却轻得多。 这个概念被用于许多早期的弹道导弹上,可部署的气钉有时被用来使导弹更紧凑。

[Trident missile with aerospike credited with extending its range by over 500 miles.][带有气钉的三叉导弹将射程扩大了500英里以上。]

国际空间站会被火烧掉吗?如果可以,看起来会是怎么样的?Can fire burn inside the International Space Station? If so, what does it look like?

It looks like this:

In the early days, planners imagined fire to be impossible in microgravity. The belief was that waste products would build up around the flame and put it out.

在早期,规划人员曾设想在微重力下不可能发生火灾。 人们认为废物会在火焰周围堆积并扑灭火焰。

This was extremely naive given that we already know fire can exist in air with too little oxygen to support life.

考虑到我们已经知道,就算空气中存在着的氧气不足以维持生命,但仍可能让火焰持续燃烧,之前那种想法就图样了。

The fire on the Mir space station put the idea to rest, and since then a steady stream of experiments have followed up.

和平号空间站发生的大火使这一想法被抛弃了,此后不断进行实验。

Fire tends to burn cooler and more slowly in space, but many of the chemicals and mechanics we use to control it on Earth don’t work in space—or can actually make it worse.

火势往往会在太空中燃烧得温度不高,更慢,但是我们用来控制地球上火灾时用的的许多化学物质和力学在太空中是行不通的,甚至会使情况变得更糟。

More work is needed.

需要更多研究。

评论区

@ Karl Chwe

Those photos are interesting. There seems to be a cooler, yellower region in the center of the flame, and a hotter blue layer surrounding it. I wonder if the yellow part indicates incomplete combustion, where sufficient oxygen has not yet diffused sufficiently into the fuel gas (I assume that the fuel is being pumped out slowly from the bottom of the pictures.)

这些照片很有趣。 火焰中心似乎有一个较冷,较黄的区域,周围有较热的蓝色层。 我想知道黄色部分是否表示不完全燃烧,此时足够的氧气尚未充分扩散到燃料气体中(我假设燃料正在从图片底部缓慢放出。)

@ Kelly Kinkade

I’m fairly certain that’s a candle; thus, fuel is being fed into the center of the flame from below by the wick. Capillary action works just fine in zero gravity.

我相当确定那和一支蜡烛相似; 因此,燃料被灯芯从下方送入火焰中心。 毛细作用在零重力下效果很好。

The yellow portions are contain particulate carbon from “incomplete” combustion, which is glowing yellow-hot but not actually burning because it’s in an oxygen-poor environment near the center, where the hydrocarbon fuel is flowing upward frrom the candle (via the wick) and being vaporized. The blue portion is the flame plasma at the fuel-oxygen interface, where combustion is actually taking place.

黄色部分包含来自“不完全”燃烧的颗粒碳,该颗粒碳发黄热,但实际上并未燃烧,因为它处于中心附近缺氧的环境中,碳氢化合物燃料从烛台(通过灯芯)向上流动。 并被蒸发。 蓝色部分是实际发生燃烧的燃料-氧气界面处的火焰等离子体。

@ Karl Chwe

I assumed the fuel was a gas, but you are right, it could be a liquid that is being vaporized by the heat of the flame. I think I thought it was a gas because the base of the flame seems attached at the base, much like a weak natural gas flame, and less like a candle, for instance.

我以为燃料是气体,但您是对的,它可能是被火焰热蒸发的液体。 我认为我认为它是一种气体,因为火焰的底部似乎附着在底部,例如很像弱的天然气火焰,而不像蜡烛。

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