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英语学堂
English Classroom |
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English Studying is getting more and more popular nowadays. |
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Is it hard? |
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No,not really |
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Now lets hit the road! |
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科技导航
Science Navigation |
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为太空行走做准备 |
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Preparing
for a Walk in Space |
Broadcast: June 4, 2003
By Paul Thompson
VOICE ONE:
This is Ray Freeman.
VOICE TWO:
And this is Steve Ember with the VOA
Special English program EXPLORATIONS.
Today, we tell about how astronauts
prepare to leave the safety of the International
Space Station and work outside in the
very dangerous environment of space.
VOICE ONE:
All astronauts who have worn protective
clothing and left a spacecraft to work
in space have told about the beautiful
sights they see. While working in space
they can see most of the Earth as their
orbit carries them around our planet.
In the stillness of space, it is easy
to forget that they are traveling at
several thousand kilometers an hour.
The great beauty they see makes it easy
to forget that they are working in an
extremely dangerous environment.
VOICE TWO:
American Astronaut Don Pettit recently
returned to Earth as a member of crew
number six of the International Space
Station. He returned to Earth with American
Astronaut Ken Bowersox and Russian Cosmonaut
Nikolai Budarin. Mister Pettit was the
International Space Station science
officer. He and the other crewmembers
spent almost six months in space. During
that time Mister Pettit wrote several
reports for the American space agency
about his experiences.
One of the most interesting reports
is about what the crew members must
do to prepare to leave the space station
and work safely in space. Doug Johnson
reads the words of American Astronaut
Don Pettit.
VOICE PETTIT:
Have you ever seen a movie about crewmembers
on a spacecraft who have to go outside
to fight evil creatures or repair a
hole in their spacecraft? They quickly
put on their space suits and leave the
ship in just a few seconds.
Well, maybe in the distant future we
may be able to do it that quickly. However,
getting ready to leave the safety of
the International Space Station can
take as long as one week. Nothing happens
fast while preparing for a trip outside
the space station.
The first thing you must know is that
no mistakes can be made. Space is an
extremely dangerous environment. Making
a mistake in space is not like making
a mistake on a school test. A mistake
in space can cost you your life.
The major problem with preparing to
go outside is the huge amount of work
that must be completed. There are many
small details but each is very important.
For example, many rubber rings are placed
between each part of the space suit
as it is linked together. Each of these
rubber rings helps prevent air from
leaking out of the protecting clothing.
Each of these rings is very important
and must be inspected. Damaged rings
must be replaced.
VOICE ONE:
Don Pettit says the first major job
that must be performed is cleaning the
small room that is the link between
the space station and outside. The astronauts
are careful about cleaning the room
because they do not want anything to
move into space by accident. A forgotten
tool or object could cause severe damage
or block their work.
This small room is called an airlock.
It has two doors -- one to the inside
of the space station and the other to
the outside and space. But as Astronaut
Pettit explains, leaving the space station
is still several days away. He explains
how the space suit is carefully put
together.
VOICE PETTIT:
The space suit comes in many parts.
We keep it in a special case. We have
a huge book that lists all of the parts
and each of the tasks that must be done.
It takes a great deal of time to read
each step that must be performed and
to attend to each detail. First, there
are the batteries that will supply the
electric power to the equipment in the
suit.
The batteries supply power for the lights
on the helmet that covers the astronaut’s
head and a video camera on the helmet.
Another battery supplies heat to the
special gloves that cover the hands.
The heat is needed to protect our hands
from the fierce cold of space.
The many batteries are inspected and
connected to the power supply of the
space station. It can take several hours
for the batteries to receive the full
amount of electricity. You do not want
to be outside and have a battery fail.
Next we work on the equipment that will
permit us to breathe. All humans produce
carbon dioxide when they breathe. This
natural gas must be taken out of the
air supply we carry.
A special device in the breathing equipment
takes the carbon dioxide out of the
air. This device has a special chemical
that must be heated in an oven for about
fourteen hours before it can be used.
This is an extremely important job.
Each piece of equipment, each device,
each link must be inspected. When the
testing and inspecting are done, we
put on the space suit for more tests.
The book has a list of tests that must
now be performed. Everything is carefully
tested following the instructions in
the book. If everything works as it
should, the tests and inspections are
complete.
VOICE TWO:
In the movies, an astronaut puts on
his space suit and is ready to go. As
Don Pettit says, it is not that simple
for real astronauts. It is impossible
for one person to put on all the necessary
protective clothing before going into
space. Everyone needs help. Don Pettit
says that like most tasks in the International
Space Station, putting on a space suit
is a team effort.
VOICE PETTIT:
At the beginning of a space walk day,
we ride an exercise bicycle. We do this
wearing a breathing device that provides
one-hundred percent oxygen. The atmosphere
inside the space station is the same
as that on Earth. The atmosphere is
twenty percent oxygen and eighty percent
nitrogen. Air pressure inside the space
station is the same as it is on Earth.
However the space suit we must wear
outside does not have the same air pressure.
If there were any nitrogen in our bodies
it would cause severe problems if we
quickly went from one air pressure to
the other. This problem is called “the
bends.” Deep-sea divers must deal with
the same problem. So, we breathe one-hundred
percent oxygen until it forces all of
the nitrogen from our bodies. We will
continue to breathe only oxygen while
we are in the space suit.
Now we begin the task of putting on
the space suit. A crewmember helps with
the many connections, links, locks and
other equipment on the space suit. Many
of the connections make a nice clicking
sound when they are linked together
correctly. We carefully listen for that
sound. Our lives depend on it. Like
all of our other jobs, putting on the
space suit is done using our list of
instructions. Nothing is left to chance.
Getting dressed in a space suit takes
about six hours from the time you start
in the morning to the time you are ready
to open the door and step out into space.
VOICE ONE:
The crewmember who is helping the astronaut
with the many parts of the space suit
has one last job to perform. The astronaut
going outside is fitted with a special
device that is linked to the back of
the space suit. This device is filled
with high-pressure nitrogen gas.
It permits the astronaut to fly back
to the space station if he were to accidentally
move too far away from the spacecraft.
Moving too far away from the space station
without this device would be a deadly
mistake. Nothing could be done to bring
the astronaut back to the space station.
The crewmember now helps the others
safely enter the room that will permit
them to enter space. Again, everything
is tested. Then the door to the International
Space Station is tightly closed and
locked. Don Pettit explains what happens
next.
VOICE PETTIT:
Slowly, the air inside the little room
is released into space. After all of
the air is gone, the door to space is
opened. My first time going outside,
the door would not open completely.
It just would not open. After all the
work we did getting ready we thought
we might have to go back inside. We
could even see the extremely bright
light of the sun showing through the
small opening on the edge of the door.
It was only a small piece of rubber
that kept the door from opening. At
the last moment, it did open and we
stepped out into space.
It really was worth the hard work. Working
outside the space station is a beautiful
experience. However, if this were a
movie about chasing bad guys in space,
I am afraid they would have gotten away
long before we were ready.
VOICE TWO:
This program was written by Paul Thompson
and produced by Mario Ritter. Doug Johnson
was the voice of Astronaut Don Pettit.
This is Steve Ember.
VOICE ONE:
And this is Ray Freeman. Join us again
next week for another EXPLORATIONS program
in Special English on the Voice of America.
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