The whole idea of leaving earth and entering into a foreign space seems exciting. It’s not like we are completely unknown to space. But how did it all begin? What gave man the idea to explore our galaxy. One of the earliest devices which applied the principles of rocket flight was the wooden pigeon which was steam powered. It was a Greek philosopher named Archytas who invented the steam powered pigeon. He was born in the 428 BC in Tarentum, Magna Graecia which is now southern Italy. In addition to being a philosopher he was also an astronomer, mathematician, statesman and strategist. The structure of the model built was cylindrical in shape with hollow insides. It had wings protruding on either sides. The front end was pointed to resemble the beak of a bird. The entire layout was structured to achieve maximum flight, distance coverage and speed.
Inside of the wooden pigeon is a bladder, this pigeon is made to sit on top of a boiling pot of water. There is a mechanical connection between the two. The boiling pot of water develops steam pressure which moves from it into the bladder. Once the steam pressure overcomes the resistance of that mechanical connection the pigeon would take off and fly.
It is unclear when the first rocket was ever invented, although it is believed that the Chinese used tubes filled with gunpowder. And when the tube was lit, it began to move forward. In the later stages of world economy the rocket was invented not with an intention of space exploration but for military purposes against other countries.
The Cold War and Space Race
The World War II ended in the year 1945. The World War gave the world a lot of technology because ‘necessity is the mother of all invention’. The radar, the Turing machine (which formed the basis for the computer), nuclear energy and much more. But it did not stop there… The World War gave birth to one of the greatest rivalries this planet has witnessed and this rivalry played out in space!
This rivalry was called the Cold War. The United States used its economic might as a weapon against the Soviet Union during Cold War. During this time, these two countries got into a competition to prove their superiority over one another in terms of technology and military power. Space was considered the ultimate frontier and thus began the space race.
Imagine being able to see what your competitor was doing, without them even knowing! After Soviet launched its first satellite, it instilled fear in the Americans since the same machinery that was used for manufacturing of that satellite could be used for warfare as well. The prevailing thought was that the Soviet could just drop bombs from space.
Since we are talking about Space, let me take this time to explain a little bit about Space and how it works.
You know how your friends say, it’s not rocket science? It’s meant to make rocket science seem really hard. It is not.
Rockets are just tubes with engines strapped to the bottom to push them really fast into space.
Imagine you are standing on top of Mount Everest. Let us say you took a satellite and threw it real hard, it will eventually slow down because of the frictional drag of the atmosphere and fall to the ground. Even though the air is very thin there, there is still enough to cause friction. If you took the same satellite and threw it faster, it would go a longer distance before falling down. Let us say that you find a source of thrust, an engine and strap it to the bottom and toss it this time, the satellite will go further because the engine pushes it faster and the friction takes longer to slow it down.
The Earth’s gravitational pull pulls it down and the frictional forces of the air slow it down.
So the problem seems to be a) speed and b) friction.
Mount Everest stands at 10 Kms tall, let us go 10 times as high; 100 Kms. Also, we were to throw the satellite incredibly fast, say at 3200 m/s. At that speed it is fast enough to continue on travelling around the earth held by the gravitational pull of the planet. Also, with the reduced friction, it would not slow down and hence would not fall back to the planet.
This is precisely what we do with a rocket launch. We take a hollow tube, put the payload (satellite, humans, whatever…) and strap on an engine at the bottom that produces thrust. We accelerate the tube to a velocity of 3200 m/s or a little more than 10,000 Km/h and get it to between 100 Kms and 35000 Kms above the earth depending on the orbit and leave it there. It continues to spin around the planet for the next 20-50 years depending on the mass of the payload and the exact altitude.
Take a bed sheet and stretch it out tight at all four corners, now drop a basket ball in the middle. The curve that you see the sheet make is what a gravity funnel looks like. The satellite continues to be bound to the planet because it is in this gravity funnel.
Escaping this gravity funnel takes incredible velocity. Appropriately it is called the escape velocity. Earth has an escape velocity of 11,186 m/s or about 40,000 Km/h. At that speed any object will be able to escape the Earth’s gravitational funnel. The moon moves at a speed that is slower than escape velocity (at about 3,683 Km/h) which is why although it is 384,000 Kms away it is still bound to the planet.
If we have to send people to Mars, we need to be able to make them travel faster than 40,000 Km/h to escape the Earth’s gravitation and move beyond the planet.
Now that we understand space… Going back.
Soviet Space Program
The birth of space age took place when Soviet pioneered into space by launching the first man made artificial satellite. On October 4, 1957 Soviet engineers made history by launching Sputnik 1 into the orbit. This orbited the earth for 3 months. Although the satellite wasn’t equipped with sensors, it provided the scientists with valuable information.
Source : Wikipedia
This was the stepping stone to the future of advanced rocketry. November 3 1958 just a couple of weeks later Soviet launched a second satellite into space, Sputnik 2. It was a lot more bigger and heavier that Sputnik 1 and it also carried a passenger, a dog named Laika.
On April 12, 1961 Soviet beat the U.S by sending the first man to outer space, Yuri Gagarin. Yuri Alekseyevich Gagarin was a Soviet pilot and Cosmonaut. He remained in space for close to two hours. The Vostok was the first human spacecraft to be built by the Soviet Union.
The spacecraft was a part of the Vostok programme. It used a dual design. It was used as a manned spaceflight and also as a camera platform. It was initially used only as a manned spaceflight but based on its design the later models were used as spy satellites. The entire spacecraft was built due to the combined efforts of engineers and scientists which was led by the Soviet Union’s pioneer aerospace engineer, Segei P Korolev.
The United States space program
Seeing the Soviet Union launch their first satellite, the Americans did not want to fall behind in the race against their rival. Since NACA (National Advisory Committee For Aeronautics)was founded during the war years to accelerate the effort to develop planes, in 1958 NACA became NASA, an independent agency of the executive branch of the United States federal government. It is responsible for the civilian space program as well as aeronautics and aerospace research.
On January 31st 1958, U.S launched its first satellite into space, Explorer 1. It was the first spacecraft to detect Van Allen Radiation Belt. Although they did face a series of unsuccessful launches before this.
An image of Explorer 1
In May of 1961, President John F Kennedy declared that America would put a man on the moon by the end of the decade. On July 20th 1969 NASA achieved that goal by successfully completing the Apollo 11 mission. Apollo 11 was the first manned mission to land on the moon. Neil Armstrong, Buzz Aldrin and Michael Collins were the astronauts who were a part of this mission. Armstrong and Aldrin took the lunar module to the moon. These were the first steps ever taken by humans on extra-terrestrial surface.
(From left to right – Michael Collins, Neil Armstrong and Edwin E. “Buzz” Aldrin)
This was a breakthrough for the Americans as no one else had achieved this in the history of mankind.