If it were not true it would be funny: yes, we are also polluting space as well as our planet. Always us, we human beings who since we have sailed through space, scatter pieces of our spaceships, our satellites and so on. Here what is space debris, real junk that somehow we are finding a way to eliminate or recover so that it does not create problems in the next missions.
What is space debris
Also called space junk, they are waste that we ourselves have left in orbit. Don't imagine banana peels, detergent bottles or bottle caps but gods fragments or entire tools that have detached from satellites, for example, over time. Or also from other devices that in the many decades of conquering space we have launched into orbit: probes, solar panels, rockets, spacecraft. If they are not pulverized, the flakes of paint are also to be considered gods space debris.
Where is the space debris
Not all of these bodies that we have abandoned in space are at the same distance and in the same area of course. They are scattered, have very different characteristics from each other and therefore different dynamics of displacement. Some are very far from our planet e they remain in orbit for years and years, indeed for centuries and centuries. On the contrary, there are those who are instead a short distance from the Earth and can cross the Earth's atmosphere within a short time.
An important and also alarming parameter is the density, because there seems to be over 8,000 tons of garbage in space and as we continue to haunt it, this figure is set to increase rapidly. Just think of the many satellites already launched, thousands, and those we are about to launch.
Space debris: are they dangerous?
If the idea of having heavy and voluminous bodies floating in space above our heads does not thrill you, you are not completely wrong. Sometimes it is not even easy to spot them as they spin in orbit, especially when they are less than 10 centimeters in size. The danger it is not so much that they fall on our heads like meteorites but that they collide with satellites that are doing their job in space. The machine itself could be damaged but a considerable risk must also be calculated for any astronauts who are operating inside it.
The extent of the damage can be high not so much due to the mass of debris but due to the speed with which they whiz into orbit. If you imagine small bodies but spinning at very high speeds, you understand that the effect is that of bullets. If they then hit the satellites in the wrong place, they can also have some explosions due to damage to batteries or contact with propellants.
As the years go by, the space becomes more and more filled with garbage and the probability of collisions increases, a bit like on our ring roads.
There are two ways to try to solve the space junk problem or at least keep it under control. On the one hand, we can understand how to bring the satellites back to Earth still intact, reusing them here. It is necessary to study well what happens when they cross the atmosphere to return, to evaluate how and how much they are damaged in this delicate phase. On the other hand, and one action does not exclude the other, you can try to eliminate some debris and here ESA comes into play, theEuropean Space Agency.
Space debris and the role of ESA
L'European Space Agency has initiated two projects to clean up the space of scattered fragments.
In the first, large space debris is identified and a net is used to hook them. It is thrown towards the debris to be captured, starting from a right distance and takes advantage of the movement of the debris itself to wrap it completely.
In the other project they are used a robot and a satellite. The latter approaches the debris to be recovered by simulating its own movement and hooks it with two mechanical arms and then brings it back to earth. Unlike the first method, this is well suited to situations where the debris is quite large.
Meanwhile, other measures have also been implemented to prevent functioning satellites from being damaged. For example, there is a system that allows the Space Station to fragment the wandering space debris so that it is also possible to absorb the various pieces created with the impact, preventing them from being thrown like projectiles on the inside, putting the astronauts in danger.
The also moved NASA designing a monitoring system to identify larger debris with Earth-based structures. The aim is to prevent and avoid explosions
The future of space debris
There is still a lot of work to be done and everyone is aware of this. There are progress that can be made on a technical and scientific level, but there is also another side of the coin that should not be overlooked because it could create several pitfalls in the near future. To date it is not possible to get rid of space debris that does not belong to one's own State, without the risk of incurring in legal charges. This, as you imagine, complicates things a lot.