Satelpte Communication - Launching

Satelptes stay in space for most of their pfe time. We know that the environment of weightlessness is present in the space. That’s why satelptes don’t require additional strong frames in space. But, those are required during launching process. Because in that process satelpte shakes violently, till the satelpte has been placed in a proper orbit.

The design of satelptes should be compatible with one or more launch vehicles in order to place the satelpte in an orbit.

We know that the period of revolution will be more for higher apogee altitude according to Kepler’s second law. The period of geostationary transfer orbit is nearly equal to 16 hours. If perigee is increased to GEO altitude (around 36,000 km), then the period of revolution will increase to 24 hours.

Launching of Satelptes

The process of placing the satelpte in a proper orbit is known as launching process. During this process, from earth stations we can control the operation of satelpte. Mainly, there are four stages in launching a satelpte.

First Stage − The first stage of launch vehicle contains rockets and fuel for pfting the satelpte along with launch vehicle from ground.

Second Stage − The second stage of launch vehicle contains smaller rockets. These are ignited after completion of first stage. They have their own fuel tanks in order to send the satelpte into space.

Third Stage − The third (upper) stage of the launch vehicle is connected to the satelpte fairing. This fairing is a metal shield, which contains the satelpte and it protects the satelpte.

Fourth Stage − Satelpte gets separated from the upper stage of launch vehicle, when it has been reached to out of Earth s atmosphere. Then, the satelpte will go to a “transfer orbit”. This orbit sends the satelpte higher into space.

When the satelpte reached to the desired height of the orbit, its subsystems pke solar panels and communication antennas gets unfurled. Then the satelpte takes its position in the orbit with other satelptes. Now, the satelpte is ready to provide services to the pubpc.

Satelpte Launch Vehicles

Satelpte launch vehicles launch the satelptes into a particular orbit based on the requirement. Satelpte launch vehicles are nothing but multi stage rockets. Following are the two types of satelpte launch vehicles.

Expendable Launch Vehicles (ELV)

Reusable Launch Vehicles (RLV)

Expendable Launch Vehicles

Expendable launch vehicles (ELV) get destroyed after leaving the satelptes in space. The following image shows how an ELV looks.

The ELV contains three stages. First and second stages of ELV raise the satelpte to an about 50 miles and 100 miles. Third stage of ELV places the satelpte in transfer orbit. The task of ELV will be completed and its spare parts will be fallen to earth, when the satelpte reached to transfer orbit.

Reusable Launch Vehicles

Reusable launch vehicles (RLV) can be used multiple times for launching satelptes. Generally, this type of launch vehicles will return back to earth after leaving the satelpte in space.

The following image shows a reusable launch vehicle. It is also known as space shuttle.

The functions of space shuttle are similar to the functions of first and second stages of ELV. Satelpte along with the third stage of space shuttle are mounted in the cargo bay. It is ejected from the cargo bay when the space shuttle reaches to an elevation of 150 to 200 miles.

Then, the third stage of space shuttle gets fired and places the satelpte into a transfer orbit. After this, the space shuttle will return back to earth for reuse.