on one night,looking at a dark sky,my friend wondered about a
. he was worried whether it was an alien's craft. he called me and i told him that it was a satellite.. Then he knew about satellite but wondered how they are launched.The launching and orbiting of satellite is based on a very common principle of physics. The earth has a force of attraction. to escape from this gravity we have to exert a force that acts towards the center of earth. a common concept of weight=reaction force determines about our life. it is because of this that we are able to walk on the ground. if by exerting some force we are able to obtain more reactrion force than the weight then we can fly and if continuously we are exerting thrust then we are able to escape the gravity.popularly termed as the"escape velocity". For this if we want to reach an altitude of 340-370km we have to accquire a velocity of 7km/s. then once we are in orbit it is necessary to maintain the orbit. to keep the satellite near earth. for this there are gyroscopes. A gyroscope is a device which determines the axis of the orientation of the space craft. for eg. satellite ISS has 3axis== X Y Z.further it is used to determine the orbit and not to maintain the orbit.
let us consider one example. a person in a golf course has striked the ball and the ball is in the air for some time and than it comes down by showing a descend of some specific angle. this indicates that by application of force, an object can be raised. so if there can be any provision which enables us in a way such that the ball doesn't come to earth. even if it comes then again it is raised before touching. Thsi is the concept!!!!!!!!! For this there are motors aboard the spacecraft which fire after specific intervals of time. they use solar energy but mostly liquid/solid propellants. they have transmitters which transmit the data on the earth by use of solar energy. if it is a weather satellite then data is in form of 1s and 2s.
the various orbits are--
1] geostationary orbit
2] geosynchronus orbit
3] low earth orbit
4] polar orbit
5] middle earth orbit
6] geosynchronus transfer orbit
7] elliptical orbit
8] elliptical transfer orbitand many more..
by--
Akshay Deoras
