Flying into Space (English subtitles available)

The programme is divided into 5 segments: 1. Action and Reaction Forces This segment uses a balloon and water rocket to explain the principle of action and reaction forces. In order to enter into space, a rocket must have sufficient propulsion force to free itself from the gravity of the Earth and push itself out of the atmosphere into space. The fact that a rocket can free itself from the gravity of the Earth and rise upwards can be explained by action and reaction forces. Gas is ejected from the rocket's engine, resulting in a strong action force. A reaction force of the same magnitude but opposite in direction arises at the same time to push the rocket. 2. Rocket's Fuel There are two major types of fuel used by rockets: solid fuel and liquid fuel. Rockets using solid fuel are simpler in structure and can create a strong propulsion force. The load of a rocket using solid fuel must be able to withstand pressure more than 10 times that of atmospheric pressure. Therefore a rocket using solid fuel cannot be used to launch a manned spaceship. The structure of rockets using liquid fuel is more complicated. The fuel is stored within the rocket and is ready for combustion in the engine. The time of combustion is also longer. This is useful in controlling the propulsion force and speed of movement of the rocket, helping the spaceship enter into and leave its orbit of the earth. 3. Rocket Design This segment introduces the difference in design of a jet plane and a rocket. The outer design of a jet plane is different from that of a rocket. A plane flies within the atmosphere of the Earth. So a plane must have a streamlined design to minimize the friction caused by air when moving forward, and to allow the wings to lift the plane. The propelling engine of a jet plane takes in air in front, accelerates it with the jet engine and jets it out in the back. The principle of action and reaction applies in propelling the plane forward. The propelling engine and fuel of a jet plane occupy only a small portion of the entire plane. However, the size of the cabin for carrying people in a rocket, whether large or small, that returned to the Earth in the end was only a small portion, usually less than 20%, of the entire rocket. Most of the rocket is used to store the fuel and oxidizing agent needed to propel the rocket. The engine of a rocket has to generate a much greater thrust than that of a jet plane. Also, a rocket has to operate in an environment without air. Therefore most parts in a rocket are used to carry liquid fuel and an oxidizing agent. Rocket cabins and spaceships explorers may have strange shapes as required by their tasks. For example, the space cabin for people that lands on the Moon is like a beetle, whereas space explorers targeting other planets may have unusual shapes. There is no need for a streamlined design. 4. In the Space This segment introduces the speeds required for a rocket to enter into space. With a strong engine and sufficient fuel, a rocket accelerates to the first cosmic speed, that is, 7.9 kilometres per second. This speed allows the rocket to go into space and orbit around the Earth. But to escape from the gravity of the Earth, the rocket has to reach the second cosmic speed, that is 11.2 kilometres per second. If a rocket has to fly away from the solar system, it has to attain the third cosmic speed, that is 16.4 kilometres per second. This segment also introduces the life of an astronaut in space, especially in a state of weightlessness. In the space cabin, the air has already been pressurized. Therefore astronauts do not have to wear special space suits, except in an emergency. This segment also gives a brief introduction of the design of space suit. 5. Back to the Earth This segment introduces what procedures and problems have to overcome when astronauts prepare for the journey back to the Earth. 6. New Mankind in the Space This segment introduces the new challenges human have to face in the future and the construction of space stations.