This is Mary Tillotson.
And this is Steve Ember with the VOA Special English program EXPLORATIONS. Today we tell about the special clothes astronauts wear that protect them while they work in space.
Many questions had to be answered about fifty years ago when officials first began to think about placing a human being in space. One of the most important was how to design the special clothing needed to protect a person from the dangers of the space environment.
A person can not work in the extremes of space without many different kinds of protection. The cold of space will freeze skin in just moments. The fierce heat of the sun can cause severe burns. The complete lack of atmosphere can cause the blood to boil.
And, with no oxygen to breathe, a human being will die in only a few moments. Any of these extreme conditions would mean a quick death for someone who did not wear special protective clothing.
When humans explore and do useful work in space, they must take their natural environment with them. The American space agency, NASA, provides astronauts with a number of things that work together to create a protective environment. An astronaut who works outside the space shuttle usually is wearing more than seventeen pieces of protective equipment.
The atmosphere is about twenty-percent oxygen and eighty percent nitrogen from Earth’s surface to where space begins at one-hundred-twenty kilometers up. Yet up at about five-thousand-four hundred meters the air pressure is only about half of what it is on the ground. At about nineteen-thousand meters, the air is so thin and the amount of oxygen so small that a person needs a lot of special equipment to survive.
A well-known American flyer, Wiley Post, designed one of the first successful devices to protect a pilot at extreme heights. In Nineteen-Thirty-Three, he developed protective clothing that made it possible for him to fly very high.
Wiley Post made this protective clothing with the help of the Phillips Petroleum Company and the B-F Goodrich Company. It appeared to be something a person would wear to stay underwater for long periods of time. A large device that looked like a can surrounded the pilot’s head. A small window in the front permitted him to see.
Wiley Post’s protective clothing was made of rubber. It could hold oxygen and provide the needed air pressure to protect his body from the lack of pressure at a high height. This rubber suit looked similar to a large balloon shaped like a human.
The protective rubber suit was only used a few times, but it permitted Mister Post to fly as high as fifteen-thousand meters. That was higher than any person had ever flown. Mister Post did not know it, but he had designed the first real spacesuit. You can see his design at the Smithsonian Air and Space Museum in Washington D-C.
As time passed, airplane designers made it possible for people to fly extremely high without wearing such protection. They did this by providing almost normal air pressure inside the airplane.
This environment meant people could wear their usual clothing. A passenger airplane today provides a safe, comfortable atmosphere inside the plane even when it is flying very high.
Astronauts in NASA’s Mercury Program flew the first American space flights in the early Nineteen-Sixties. Each set of protective clothing was specially made for each astronaut. The clothing was similar to that invented by Wiley Post. And, it presented some of the same problems.
When air pressure filled the early spacesuit, astronauts found it difficult to move their arms or legs. It was a little like trying to change the shape of a balloon. The pressure inside the suit provided protection, but made it difficult for the astronaut to move in a natural way.
Mercury astronauts usually wore the suit without air pressure inside. The Mercury spacecraft had the needed atmospheric pressure to keep the astronauts safe. The astronauts wore the suit as a safety device in case the spacecraft suddenly lost air pressure.
Today, astronauts wear very different protective clothing. It permits them to move, do useful tasks, and stay out side their spacecraft in comfort and safety for several hours.
For the next few minutes, imagine you are in the space shuttle about to go out to work in space. We will tell you how you need to get into your space clothing.
You will wear a spacesuit to work in the open cargo area of the Space Shuttle Discovery. The spacesuit is called the shuttle extravehicular mobility unit or E-M-U. It was designed to last longer and to permit more movement than earlier spacesuits.
The E-M-U has a number of parts that an astronaut can link together by using only one hand. The different parts are in different sizes. This makes it possible for each astronaut to select the parts that fit correctly.
Wearing the whole E-M-U equipment adds about forty-eight kilograms to your weight. Yet, the lack of gravity in space means you will not feel the added weight.
You will be wearing equipment that will send medical information back to the NASA control center in Houston, Texas. Doctors will observe your medical condition while you work in space.
You also will wear a device that will collect urine, the body’s liquid waste. You will be working outside the space shuttle for about five hours. This collection device can become very necessary.
You will also wear something called the Liquid Cooling and Ventilation Garment. This piece of clothing is worn next to the skin. It helps keep the body cool by moving water through many small tubes that cover the device.
The heat from the sun can reach one-hundred-twenty degrees Celsius in orbit. The material of the space suit helps protect against this heat. The liquid cooling device also works to keep your body from becoming too hot.
Next you put on a container that holds water to drink. The container is worn near the chest. A small tube stays near your mouth so you can drink water during your stay in space. You place a special hat on your head. It is made of soft cloth. It also carries several communications devices including earphones and microphones.
These communication devices will permit you to talk with other astronauts working outside the shuttle and with crew members inside the shuttle. You can also talk with the control center in Houston, Texas.
The lower part of the spacesuit is next. It is called the Lower Torso Assembly. It is like putting on a large pair of pants that have boots built in the bottom of the legs.
Next comes the upper part of the spacesuit. It is made of a hard plastic-like material. To put it on, you must hold your arms over your head, and rise up into the upper part of the suit. The upper part of the suit also holds the Primary Life Support System.
The life support system supplies the oxygen needed for breathing and the air pressure necessary to protect your body. The upper part of the spacesuit also carries an emergency oxygen system in case the first system fails.
An important part of your spacesuit is the Control Module. It lets you observe and control your oxygen system. It is also the place you find the controls for your communications equipment. And, it tells you if you are having a problem with any of the spacesuit’s devices.
It is time for you to link the many systems together. The oxygen is on so you can breathe. And the air pressure is producing a normal atmosphere to protect you. Now you are ready to enter the work area of the space shuttle Discovery.
You will need one more piece of equipment. This is the Manned Maneuvering Unit, or M-M-U. It connects to your Primary Live Support System. It makes it possible for you to fly from place to place in space, away from the Discovery.
The M-M-U is worn on the back. It is controlled by a device that is held in the hand. The jets of nitrogen gas from the M-M-U help you move. The pressure of this gas moves you through space.
You are now ready to work in the extreme and dangerous conditions of space. You will be comfortable and able to move. You can do the work that is needed. Then, best of all, you can return safely into the space shuttle when your work is done.
This Special English program was written by Paul Thompson. It was produced by Caty Weaver. Our studio engineer was Kevin Raiman. This is Mary Tillotson.
And this is Steve Ember. Join us again next week for another EXPLORATIONS program on the Voice of America.