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8 tháng 5 2019
Astronauts in Training 05.27.04

The most exciting day for anyone who wants to travel into space is the day he or she is selected to be an astronaut candidate. Then the real work begins. It can take up to two years of training to become a fully qualified astronaut. Candidates must learn the basics of the Space Shuttle and the International Space Station. They must also learn how to be part of a team by flying the NASA T-38 training jets.

The 2004 astronaut candidate class
Image above: Being selected to be an astronaut candidate is exciting. Credit: NASA


Astronauts also take classes. They must learn many things besides science. They also learn about medical procedures. Many times, they have to give speeches, so they take public speaking classes. In order to be prepared for any emergency, astronauts take survival training.

If you are going to be a crew member on the ISS, you will also have to take language classes. You will need to be able to talk with the Russian Mission Control Center.

Space Vehicle Mock-up Facility

Space Vehicle Mockup Facility

Image to left: In the Space Vehicle Mockup Facility, astronauts practice what they will be doing in space. Credit: NASA

In order for astronauts to get a feel for what they will be doing in space, they practice on life-sized models. These models are called "mock-ups." The Space Vehicle Mock-up Facility (SVMF) is where they practice. In the SVMF, astronauts practice using the Space Shuttle Orbiter and parts of the ISS. In these mock-ups, astronauts will learn how they will move about.

Preparing for Microgravity

How do astronauts practice for being in space? There are many things to learn about being in the almost weightless condition known as microgravity.

KC-135

Image of the KC-135

Image to right: Astronauts feel weightless for a short time in the KC-135. Credit: NASA

This plane is also known as the Weightless Wonder or Vomit Comet. It provides about 20-25 seconds of zero gravity. For this brief amount of time, astronauts feel weightless. Sometimes, even experienced astronauts get sick in the KC-135. That is where it gets one of its names.

The Precision Air-Bearing Floor

The Precision Air-Bearing Floor

Image to left: Astronauts learn how to move large objects in space using The Precision Air-Bearing Floor. Credit: NASA

One part of an astronaut's work may include moving large objects in space. This can be easy because there is no friction to push against. But, this also makes the job hard. There is no friction to make the large objects stop! They could float and float and float.

The Precision Air-Bearing Floor allows astronauts to move huge objects as they might in space. It is a large, smooth metal floor. The large objects have air forced through them. It is like a large air hockey table.

The Neutral Buoyancy Laboratory

Two astronauts in the Neutral Buoyancy Laboratory

Image to right: Astronauts use the Neutral Buoyancy Laboratory to practice extravehicular activities. Credit: NASA

To practice extravehicular activities, or space walks, astronauts go underwater. The astronauts use the Neutral Buoyancy Laboratory (NBL), a huge "swimming pool." The NBL pool is 62 meters (202 feet) in length, 31 meters (102 feet) in width and 12 meters (40 feet) in depth. The pool holds 22.7 million liters (6.2 million gallons) of water.

Astronauts float in the water while they practice on full-sized models of space vehicles. They may spend up to seven hours at a time under water.

Although astronaut candidates may have their college degrees, school is just beginning for them when they are selected. There is still much to learn.

26 tháng 4 2021

Cũng ko rõ

5 tháng 5 2021

In the past, people didn't think children will be ones building a country. However, in the future, this view will changed. Teenagers are the next generation, who will be controlling and running the world someday. As a result, teenagers play an important role in society. What they do, what they accomplish, what they are exposed to has every effect on, not only our personal future, but the future of society as a whole. If they develop well, study hard and are always creative, their community will be getting more and more modern. Clearly, every generation grows up in a completely distinct world. The prosperity of a country in the future depends on the teenager generation. As teenagers, we need to have faith and power within ourselves. We need to have initiative. We are in charge of the future generations. If we don’t make a change ourselves, how will improvements in society occur?

 

20 tháng 6 2021

Tham khảo nha!

 

The environment is of great importance to human life. Each of us must have a sense of responsibility, together to build a cleaner and cleaner living environment.
First of all, in order to keep the school green, we have to plant and care for the trees in the school together. Every year, we have to participate fully in the plantations of the School Union. We will take care and protect the trees on the school grounds. Trees must be protected and care, not picking flowers, breaking branches. Especially the boys, should not climb the trees in the school. You should not climb flowers on phoenix trees, linden trees ... Our beloved garden will be greener if all of us are aware of the care and protection of trees. Classes will have to do the planting and tree care in the garden, school yard.
Every family, every citizen should have a sense of environmental protection. Clean house, clean village, clean street, clean school, clean hospital is the striving direction of the whole society. Shady trees, gardens will make the street scene more beautiful. No one throws rubbish out into the street, out in public. Scientific measures should be taken to treat industrial waste. Open canals, fill ponds, open the streets to make the environment green, clean beautiful. "A day without plastic bags" - the slogan should be implemented by the entire population

Eat a candy, before dropping it on the road, thinking about how it can affect the environment. Be knowledgeable people, to protect yourself and the people around you. What did you do?

14 tháng 10 2021

Bạn tham khảo nhé: 

   Mobile phones provide the freedom to quickly connect with anyone around the world. They enable us to find any information that we need and is a great source of entertainment. While this invention was done with the aim of empowering us, sadly, it is something that is dominating us. These days, most mobile users are suffering from mobile addiction.

Can do so on a mobile phone. Our mobile phones enable us to engage in gaming, gambling and online shopping. They connect us with people around the world, allowing us to watch movies, click pictures, listen to music, surf the internet and enjoy various other activities. It is difficult not to be accustomed to this electric house of entertainment.

However, it is necessary that it does not have any prey. This is because its results can be harmful. Mobile addiction causes many serious problems, such as headaches, weakening of eyesight, sleepiness, depression, social isolation, stress, aggressive behavior, financial problems, wasted relationships and less or less professional development.

Mobile phones have been made for our convenience. We should limit their use to handle our lives. If you think you are becoming addicted to your mobile phone, then see ways to get rid of it. You should also take it as your responsibility to help you get rid of this addiction of your loved ones.

 

11 tháng 6 2021

make me feel stress \(\Rightarrow\) makes me feel stressed

which are hundred \(\Rightarrow\) with hundreds

 at myself and things \(\Rightarrow\) in myself and the things

the mirrow and speak outloud \(\Rightarrow\) the mirror and speak out loud

11 tháng 6 2021

Tham khảo

One of the causes which always make me feel stress is public speaking. It's also one of people's worst nightmares because they don't enjoy standing in front of a group of people which are hundred eyes looking at them. I know how it feels but I get over it easily. How? I believe at myself and things I have prepare for my presentations. I also practise a lot by standing in front of the mirrow and speak outloud. 

7 tháng 5 2018

Hello everyone, today I'd like to tell you some information about types and sources of energy. Energy is classified into two main groups: renewable and non-renewable.

The energy generated from natural sources such as the sun, wind, rain, and tides is called renewable energy. They are plentiful and can be generated again and again. They also have low carbon emissions so they are considered green and environment-friendly. Moreover, using renewable energy can reduce your electricity bills. Unfortunately, solar energy can be only used during the daytime but not during night or the rainy season. Geothermal energy also can bring toxic chemicals beneath the earth's surface to the top and can create environmental changes.

Non-renewable energy is the energy taken from other sources that are available on earth.They are limited and will run out in the future. They can't be re-generated in a short time.Fossil fuels - natural gas, oil and coal - are examples of them. They are cheap and easy to use. However, when burnt, they release toxic gases in the air so they cause serious environmental changes such as global warming. And the important thing is that non-renewable sources will expire someday.