Life span of satellites

India is all set to launch its maiden Moon Exploration Mission Chandrayan-1 and every Indian is very thrilled & excited about the same.
But here I would like to discuss about the life span of satellites.


Like every starting has a ending in the universe, the satellites also will die after specific span of time which is called “Life Span”. For example; The scheduled “Chandrayan-1” mission’s life is 2 Years.
The life span of satellites depends largely on their size, or to be precise , it depends on how much liquid fuel they carry aboard . The liquid fuel is used to operate small rocket engines, the rocket engines are very important for the satellite (there are three types of forces acting on the satellite in space causing the satellite to deviate from its course). The ground station on earth uses these small rockets to perform maneuvers necessary to keep the satellite in the same position in the sky (usually they perform two maneuvers every two weeks, north-south maneuver & east-west maneuver). So we can direct our antenna's here at earth(parabolic reflectors or dish) to this specific point in space & receive the broadcasted TV & radio channels & also to send tele-commands from the ground station on earth to control the satellite , otherwise we need a special type of antenna's (half a billion US$ each) to track & locate the satellite.

The largest satellites out there are the communication satellites (tv, radio, telephony) & they use the geostationary orbit (about 36,000 km above sea level & above the equator) & the satellite orbit around the earth depends on the speed of the satellite, once the satellite is delivered to its orbit by the rocket it was carried on, the satellite will take that orbit speed, comm. sat. also have the longest life span (it’s a round 17 to 20yrs these days) , before the satellite runs out of fuel , the ground station performs one last maneuver to send the satellite to a place called “satellite graveyard”. It’s an orbit around the earth used to retire old useless satellites & they become junk on space, a growing problem, this is when in it come to satellites using the geostationary orbit , for satellites using lower orbits they may be put on re-entry course so they burn before they reach the earth.