I saw a very interesting phenomenon at the NASA exhibition in Seoul, South Korea: fake things are rushed to see, and real things are not known how to see.
Watching the exhibition costs money and spends time, unless you know very well that your purpose is just to take photos, punch cards, upload, otherwise if you can know a little more about the content before watching the exhibition, then you will know more about what doorway to see when watching the exhibition, and you can also type a few more words when uploading FB, so that your friends know how powerful this thing is in the photo!
What is the "fake thing" in the exhibition hall and what is the "real thing". When I talk about "fake things", I don't mean that the curatorial unit deliberately shows you fake things, I will give you an example, like rockets and spaceships have been shot into space, how can they come up with the real thing to show you? In order for the public to understand what it looks like, a "model" is needed to display it, so that everyone can visually feel this thing that cannot appear on the scene. So what is "real stuff"? Fragments of the V2 ballistic missile displayed in the glass cabinet are important authenticities. The V2 ballistic missile was the world's first long-range ballistic missile, appearing during World War II. Although its appearance does not look as dazzling as a rocket model, if you want to appreciate an exhibit more deeply when watching a special scientific exhibition, you will have different feelings when you put your feelings and history together.
Then let's return to the scene of NASA's special exhibition Korea:
4. Pioneer Pioneers
Photo/Author photography.
This exhibition area introduces many important rockets and engines.
Here you can see the SATURN V rocket, the largest rocket ever built, reaching an altitude of 110.6 meters. The Apollo plan to land on the moon was to use the Saturna v rocket. I often hear a misunderstanding of the name of the rocket. The name SATURN V does not refer to the rocket of "this rocket", but to "this type of rocket", SATURN V launched a total of 13 times, armstrong they landed on the moon is the 6th.
13 launches of SATURN V. By Maldoror – nasa.gov, Public Domain, wikipedia.
As you can see from the photo, at the very front end of the rocket, there is something like a spire, which is actually the launch escape system (LES) of the Astronaut's escape device. After the astronaut boards the rocket, if there is a problem in the early stage of the rocket launch process, LES will take the astronaut away from the rocket, and when the rocket lifts off to a certain altitude, LES will detach from the rocket in order to reduce the weight, and if the rocket has a problem after that, the astronaut will be able to ask for more blessings.
Launch escape system for SATURN V.
Look at SATURN V from the other direction. fig
In addition to the most eye-catching SATURN V, there is also the titan I engine. Some rockets will be staged, section 1, section 2, section 3 is counted from the bottom of the rocket upwards, and the bottom is called section 1. The TITAN I was the first multi-section intercontinental ballistic missile in the United States with two sections. The purpose of the rocket is to send the spacecraft or satellite (these will be called the payload of the rocket) into space, but the weight of the rocket far exceeds the payload itself, that is to say, the spaceship or satellite itself is not heavy, the weight is the rocket that sends it into space. So in order to reduce the weight, after the rocket runs out of fuel, it will disengage the first stage 1, and the second section of the engine ignition continues to fly into space. But don't think that dividing the rocket can reduce weight, so the more sections the better. Because although the section has the benefit of weight reduction, it has the following disadvantages:
1. Detachment from failure
The rocket section is locked together with something like "bolt", and when it disengages, it is broken with an appropriate amount of gunpowder, and if the process of blowing up the bolt is not smooth, it may fail to break away.
2. Ignition failed
After the first rocket disengages, the engine of the second rocket will be ignited. Just like the electronic ignition of the gas stove in the home, sometimes the first fire is not lit, we can light the second and third times. The first section of the rocket is ignited on the ground, and if the ignition fails, it can be remedied; the rocket above the second section must be ignited in the air, and if the ignition fails, the task will be played.
The above two points must be carried out in the air, two rockets (TITAN I) to do one air disengage + ignition, three rockets (SATURN V) to do two aerial disengagement + ignition. These actions are more and more dangerous the more you do them.
3. Too many engines
Each additional section requires the addition of a set of engines, which not only take up the weight, but also cost money. So too many knots will also have too many disadvantages of the engine. Before launch, only the first section of the engine is exposed, and the engines above the second section are wrapped in the rocket body, so when you look at the TITAN I engine at the exhibition site, you don't have to look at the instructions to know which one is the first section, because the first section will grow larger.
4. The structure becomes weaker
A complete rocket, if it is divided into too many sections, wants to know that the strength of the entire structure will be reduced, which is also a disadvantage of the section.
There is a very conspicuous cowboy hat in the display case, this is Warner, the father of rockets. Feng. Wernher von Braun's, although not directly related to space science, is also an important historical artifact. The fragment next to it is the fragment of the V2 ballistic missile that I mentioned earlier in the world that appeared during World War II, the V2 ballistic missile.
The number 5 is Warner. Feng. Brown's cowboy hat; number 3 is a fragment of the world's first long-range ballistic missile, the V2 ballistic missile. fig
In this display case are models of various rockets and shuttles, all at 1/72 scale. You can compare the sizes of various rockets.
1/72 model of various rockets.
Finally there was one thing I thought was cute, there was a piece of glass at the entrance of the exhibition area, which felt like a transparent blackboard. It's a great place to take pictures, where people can stand on the side of the glass and pretend to explain the principles of the spacecraft's orbit to others, and the person taking the picture will take pictures from the other side of the glass.
Glass at the entrance to the exhibition hall. The male anchor of the same medium-sighted type made an interview with the author in front of this glass. The film will be broadcast during the special exhibition's strong publicity.
The formula above this piece of glass and the figure I briefly introduce: everyone in the middle school has learned F =ma, this is Newton's second law of motion, F is the force, m is the mass, in many cases on the earth is directly equal to weight, a is acceleration. In a very loose vernacular, I put it in "it takes effort to speed up something, it takes effort to slow down something, and the heavier the weight of the thing, the greater the force." Without any resistance (nor air resistance), it does not take strength to keep something as fast (a = 0) all the time. Things around us often increase or decrease in speed, and schools also have topics that tell us how much it takes to accelerate an object of 100 kilograms from rest to how much effort it takes. Pay attention to this topic: it tells you that the "100 kg object" has actually been set to the mass of the object is fixed, but the mass of the spacecraft in space will change, such as disengagement, fuel reduction, or putting things on the moon, bringing stones back from the moon, etc., will change the mass of the spacecraft, so when using the formula F=ma, not only a will change, m will also change. (If you say the previous passage in front of this glass, you should be able to scare some people!) ）