Main->Readings->5th Grade Readings->Human Spaceflight->Part 4
Vocabulary |
In the beginning, the Soviet Union dominated the space race. They were the first to orbit a satellite, the first to send a living creature into space, and the first to send a human being into space. With a little time, the United States always managed to do the same thing, but it always seemed to come in second. This was not because the U.S. started late, but because it took longer to plan and test its missions. Also, the Soviets kept the details of their missions secret, and it has not been until recently that we have found out many of the risks they took on their way to space.
The United States had already begun serious plans for spaceflight in October of 1958, when President Eisenhower created the National Aeronautics and Space Administration (NASA). NASA promptly announced the first manned space program, Mercury, and in 1959 the first seven astronaut candidates were named. These were the famous "Mercury 7":
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Astronaut Groups 1 and 2
The original seven Mercury astronauts selected by NASA
in April 1959, are seated (left to right):
L. Gordon Cooper Jr., Virgil I. Grissom, M. Scott Carpenter,
Walter M. Schirra Jr., John H. Glenn Jr., Alan B. Shepard Jr.,
and Donald K. Slayton.
The second group of NASA astronauts, which were named in September, 1962,
are standing (left to right):
Edward H. White II, James A. McDivitt, John W. Young,
Elliot M. See Jr., Charles Conrad Jr., Frank Borman, Neil A. Armstrong,
Thomas P. Stafford, and James A. Lovell Jr.
Picture courtesy of NASA
Johnson Space Center Digital
Image Collection
February 23, 2000, accessed July 19, 2000
http://images.jsc.nasa.gov/
Yet the second human being to orbit the Earth was Gherman Titov, another Soviet cosmonaut, and the first American in space, Alan B. Shepard, didn't even orbit the Earth when he went up only three weeks after Yuri Gagarin. He made a suborbital flight, meaning that he went up into space but came right back down without orbiting the Earth.
The first United States astronaut to orbit the Earth was John Glenn, on February 20, 1962, nearly a year after the successful mission by Gagarin. The citizens of the United States were relieved and excited that Glenn had made it, and made a hero out of him.
John Glenn in his suit
Picture courtesy of NASA
Johnson Space Center Digital
Image Collection
February 23, 2000, accessed July 19, 2000
http://images.jsc.nasa.gov/
As time passed, more men (and some women, in the case of the U.S.S.R.) made Earth orbits, and the space commands of the two nations became more experienced in planning and executing their missions. Yet in all these flights, the astronauts and cosmonauts were sealed inside their capsules, protected by layers of metal from the endless vacuum of outer space. What would happen if a space-craft needed to be repaired, or if people wanted to build space stations? Were there ways that people could move about and work in space without going insane from the lack of weight, the disappearance of "up" and "down," and their distance from Earth? This was not answered until 1965, when both the U.S.S.R. and the U.S. planned their first "space walks."
Once again, Soviets were the first to achieve the goal. On March 18, 1965 the Russian spacecraft Voskhod 2 was launched, with Pavel Ivanovich Belyayev and Alexei Arkhipovich Leonov aboard. Leonov, who was to be the one to go outside, was wearing a new kind of space suit which would allow him to move easily, and protect him from the glare of sunlight. He had a radio inside his helmet, and a long lifeline would attach him to the ship. Inside the ship, Belyayev was wearing a similar suit in case a rescue was necessary, but it was Belyayev's job to pilot the ship while Leonov went outside.
Because there was no air outside in space, they could not just open the door and walk through. All the air inside the capsule would rush out and leave Belyayev without anything to breathe. So they had to use something called an "air lock." It was a small chamber between the capsule and the outside. Leonov went into the air lock and sealed the hatch behind him. Then he opened the hatch to the outside, and though the air in the air lock rushed out, it was only a small amount, not the whole ship's supply.
Leonov pushed himself carefully head-first out of the opening. Empty space was all around him, blacker than any Earth night but with stars brighter than anyone experiences on Earth. Leonov gently pushed himself away from the ship, drifting out as far as his lifeline would allow. If it broke, he would drift forever into endless space. Slowly, the 16-foot line stretched to its full length, and stopped, and he floated at the end of the line.
Newton's laws of motion work just as well in space as they do on Earth. Leonov's line pulled on the spacecraft, and there was no friction to keep Voskhod itself from turning gently in response to the tiny push. Leonov was in free fall along with Voskhod, and though the two of them were traveling at an immense speed, there was no air to rush past and tell him how fast he was going. At the end of his lifeline, he was spinning slowly, now looking at space, now looking down at the huge Earth turning below him.
Could a human being stand the immensity of space? Would Leonov be terrified of being exposed to the infinite distances all around him, or afraid of falling back to Earth? Well, when his ten minutes were up and Belyayev told him to come back, he didn't want to return. He was having too much fun.
Leonov outside
Picture courtesy of NASA
Starchild:A Learning Center for Young Astronomers
http://starchild.gsfc.nasa.gov/docs/StarChild/shadow/space_level2/leonov_spacewalk.html
Ten weeks later, on June 3, the U.S. conducted its own space walks. The Gemini 4 spacecraft, carrying James McDivitt and Edward White, went into orbit. White also had a lifeline like Leonov's, 25 feet long instead of 16 feet, but he carried something else which gave him control over his movements.
One of Newton's laws of motion states that for every action there is an equal and opposite reaction. This is what allows rockets to work. They send gas or other reaction mass from one end of the rocket at a high speed, and the rocket goes in the opposite direction. Edward White was carrying a miniature rocket of his own, a propulsion gun which fired only air. But when he shot the air out under high pressure, White himself went in the opposite direction from the air-jet. He could move around in any direction he wanted, just by aiming the gun the other way. At the end of his lifeline, he experimented with the gun, having so much fun that he too did not want to return when McDivitt told him his time was up.
Edward White outside Gemini 4
with a propulsion gun
Picture courtesy of NASA
Johnson Space Center Digital
Image Collection
February 23, 2000, accessed July 19, 2000
http://images.jsc.nasa.gov/
We thought the problems of space walks were solved. Human beings had proved they could stand endless space and even enjoy themselves, and we had figured out a way to move around. But when astronauts tried to actually work in space, they found there were other problems. If you turned a screw with a screwdriver, for instance, there was no weight to allow you to brace yourself, and you yourself also turned in a circle, in the opposite direction from the screw. If you banged something with a hammer, you floated the other way from the force of the blow. Newton's laws presented some unexpected difficulties. Astronauts had to experiment for some time, both in space and in underwater tanks where the conditions were similar to weightlessness, before they figured out ways to solve these problems.
These days, astronauts consider "space walks" almost routine. The shuttle crews climb all over space stations and orbiting telescopes, and they go out on the surface of the shuttle to repair and place satellites into orbit. Though they must protect themselves against vacuum and floating away, and be careful not to let go of tools that might become satellites themselves, astronauts are familiar with the conditions of working in space. However, when Leonov and White made their first steps into vacuum, no one knew if they would be coming back. The first time is always an unknown.
Go on to Part 5: To The Moon: The Apollo Program
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This page last modified on August 15, 2002