Satellites are sometimes a moon, a planet, or man-made machines that orbit around celestial bodies like planets or stars. Planets like Earth are examples of a satellite because they orbit the sun. It is the same as the moon as our satellite because it orbits our planet, Earth. There are two kinds of satellites, a natural satellite, and an artificial satellite. The planets and the moon are examples of what we call a natural satellite while man-made machines that are made to orbit the Earth and all other planets are what we call an artificial satellite. Artificial satellites are made to help meteorologist track the weather conditions and foresee the storms coming through the help of the pictures of the planet taken by these machines. Some artificial satellites help astronomers identify, understand, and have a better view of astronomical objects like the sun, stars, other planets, black holes, and many other galaxies. Artificial satellites also help in communication and the Global Positioning System in the world.
However, artificial, or man-made satellites have a tight lifespan. Like any other machines and equipment, satellites also crash and deteriorate as time passes by. Satellites usually have a lifespan of 5 to 15 years depending on the satellite. Low-altitude satellites orbiting the Earth have a shorter lifespan than that of geostationary satellites. The Vanguard 1 Spacecraft is the oldest artificial satellite of Earth that is still orbiting until now. It does not communicate to Earth anymore, but it is still in orbit and will probably remain in orbit for a very long time.
WHERE DO OLD SATELLITES GO WHEN THEY DIE?
What happens to a satellite when it dies depends on its altitude or its position in space? Low altitude satellites and high-altitude satellites have different ways of deteriorating and detriment.
Low Altitude Satellites
Satellites orbiting in a low altitude close to Earth are usually navigated closer to the planet. Engineers will most likely use the satellite’s last amount of fuel to maneuver it down slowly. That would help the satellite fall out of orbit and enter the Earth’s atmosphere, and from there, it would burn up.
High Altitude Satellites
What happens to satellites on higher altitude when they die are quite different from the satellites on a lower altitude. The amount of fuel required for geostationary satellites to come back to Earth after they die is very heavy, making it impossible for them to be put in space. Satellites on higher altitude usually require a greater amount of fuel to be maneuvered down slowly in the atmosphere than to blast off. Instead of coming back to Earth, these satellites are positioned into a much higher altitude away from Earth or known to be the “graveyard” orbit.
WHAT IS A GRAVEYARD ORBIT?
A graveyard or what we also know as junk orbit is not technically an orbit but is somewhat a region where old and dead satellites are put into place to not crash into satellites that are still working perfectly fine. There are placed very far from Earth with a distance of approximately 200 miles.
One example of a dead satellite that went to the graveyard orbit is the Meteosat-7. Meteosat-7 is an example of a spinning satellite that belongs to weather satellites that provide weather forecasts and warnings to the Earth. This satellite degraded after almost 20 years of orbiting the Earth, which is more than enough considering that its expected lifespan is 15 years only. This dead satellite was maneuvered to the graveyard orbit where it can finally rest.
The moment the dead satellite reaches the graveyard orbit, preventive measures are carried out to avoid the possibility of the breaking up the satellite in the future. Residual propellants are depleted, leftover gas in the tank system is pressurized, batteries are made sure to be discharged and disconnected, pyrotechnic devices that are not in use will be fired, and almost all equipment on the satellite are switched off.
There are now over hundreds of dead satellites in the graveyard orbit. The number of man-made satellites launched on space is increasing every year and numbers of dead satellites are also increasing. The graveyard orbit is only a temporary solution for the dead satellites. This means that their will come when the graveyard orbit will be too overcrowded and will not be able to cater to more dead satellites because they might crash into each other and might produce space debris. Scientists are researching for permanent solutions that include collecting and removing old dead satellites.