ASTRONAUTICS

To know about the astronautics, we have to know about Astronomy. Astronomy is the scientific study of the stars, planets and other heavenly bodies it understands it, men have watched the sky and have tried to explain what they have seen there. The astronomer, like any other scientists needs a laboratory is called instrument is telescope. So, astronautics deals with astronomy by the different medium. Astronautics is the branch of science which deals with the many problems of space flight.

 The space age begins with the launching of artificial satellite 10^th October 1957, less than 4 years later on April 12 1961, came the first manned flight. The Russian Yuri Gagarin made one orbit of the earth in his space craft vostok1. He was the 1^st space pilot, of astronaut. After years of preparation the US landed a manned space craft Apollo 11, on the moon on July 20, 1969. In the next few years several more successful moon landings were achieved by the USA and valuable scientific experiments were helped in these by the small vehicles on moon buggy, they took with them. A space craft is carried into space on the top of massive rocket, which lifts it clear of the earth’s atmosphere and gives it the very high speed required to keep it in orbit or propel it to the moon. A space craft can stay in orbit if it has enough speed to overcome the pull of the earth or gravity =. For an orbit 100 km above the earth, this orbital velocity is 28000 km/hr. at this distance and orbital velocity the tendency of the space craft to fly away from the earth is balanced by the gravitational pull.

There is then no effective gravity on orbit. Everything is therefore weightless. This state is often called zero G where G stands for gravity. The space craft must be lifted above the earth’s atmosphere to avoid the resistance, or drag of the air. Drag would quickly fall back to the earth. Also fiction with the air would heat the craft and might even make it burn up, just like a meteor does. The meteors are heavenly bodies that may be seen in the sky of moon less at night as flashes of lights. They are not stars; however, their appearance has given rise to their common name, shooting stars. The sizes of meteors vary from small dust particles to large structures weighing many tons. The dust particles break up of comets the large structures are pieces of asteroids after their collision.

Launching an astronaut into space and bringing him back is a very hazardous business. To start with, he has to stand with the great forces of acceleration during take off. Then he must adjust to the effects of weightless in orbit. He must be protected by spacecraft or spacesuit from cold and airless world of space. He must survive the rapid slowing down and heating effects caused by the drag of the atmosphere. Astronauts receive special training to prepare themselves for space flights. For example, they spend a long time in a machine called centrifuge, which whirls them round and round rapidly and reproduces the kind of forces they can expect during the take off and landing. The astronauts also train in dummy space craft which can be made to do many of the things as a real one does in space. After months of intensive training, the astronauts climb into their space craft and are rocked into space. They lie on their backs during launching because that is the best way to with stand the great ‘push’ of the rocket.