Methods to place Satellite into Geostationary orbit

Methods to place Satellite into Geostationary orbit

There is a considerable amount of expertise and technology used to ensure that satellites enter their orbits in the most energy efficient ways possible. This ensures that the amount of fuel required is kept to a minimum; an important factor on its own because the fuel itself has to be transported until it is used. If too much fuel has to be used then this increases the size of the launch rocket and in turn this greatly increases the costs.

Many satellites are placed into geostationary orbit, and one common method (1st method) of achieving this is based on the Hohmann transfer principle. This is the method use when the Shuttle launches satellites into orbit. Using this system the satellite is placed into a low earth orbit with an altitude of around 180 miles. Once in the correct position in this orbit rockets are fired to put the satellite into an elliptical orbit with the perigee at the low earth orbit and the apogee at the geostationary orbit as shown. When the satellite reaches the final altitude the rocket or booster is again fired to retain it in the geostationary orbit with the correct velocity.

as shown in the fig the perigee of the transfer orbit intersects the LEO orbit.This point is 1st pro-grade burn i.e rocket thrust (called delta V) in the same direction as of orbit and transferred to elliptical orbit i.e Hohmann Transfer orbit or Geostationary Transfer orbit.

at half of the transfer orbit is apogee point which intersects the geostationary orbit after that point satellite starts to fall i.e we have to fire our thrust in the same direction of the orbit which is 2nd pro-grade burn to remain in the geostationary orbit.

( 2nd method )Although now-a-days almost all the county uses Expandable Launch vehicle which directly place satellite into geostationary transfer Orbit without using LEO. ( PSLV , GSLV is expendable launch vehicle use by India)

But hohmann Transfer orbit is very useful for interplanetary travel (travels to diffrent planets by including one more method called gravity Assist )

America NASA's Space shuttle and Russia's Soyuz are Partial reusable launch vehicle to carry payloads to LEO orbit (ISS is in LEO orbit) while PSLV GSLV (india), Ariane 5 (ESA),Proton M (Russia) are expandable launch vehicle i.e non reusable vehicle.

no true reusable launch system is currently in use.