Ever since we discovered that Saturn has rings, we have been amazed and mesmerised by its beauty. We always dreamt to have one such ring for earth as well. It was once considered impossible. But the fact has changed. Earth has developed not just 1 ring but hundreds and thousands of rings that somehow covers our entire earth.
Also these rings are not made of ice and rocks like how saturn rings are made. These are created by humans. The fun fact is we humans never thought of doing such things intentionally. Also the irony is these rings don't make earth beautiful, they make it look more nasty.
I hope you get it. The space debris or the space junk. Little to no importance had been given for these junks during its earlier stages. But the current situation is getting out of control. Let us begin our journey about space debris and we could prevent it from accelerating.
What is space debris:
For the past 60 years we have been sending a lot of satellites to space. More than 10000 satellites have been launched. Most of them are dead by now. These satellites along with the different stages of the rocket are lurking around us.
As our rocket launches have been steadily rising, space junk is becoming more of a crisis now. The dead satellites and other big objects actually pose less threat than the debris that are less than 1cm to 1 mm in diameter. You probably should be surprised by this.
But these big objects can be easily identified and spaceships that have humans and other operating satellites can easily manoeuvre. However tiny particles like nuts, bolts and even small paint particles cannot be easily tracked.
You might ask how a 1 cm object is going to obliterate an entire spacecraft. But never underestimate something by its size. Although these minuscule particles seem harmless, their speed makes them fierce. Travelling at an average speed of 27,000 km/hr, a 1 cm object is more than enough to finish a spacecraft.
So all these rocket leftovers, dead satellites and other millions of tiny and small objects form the junk cloud called the space debris. Currently there are over 130 million objects orbiting earth between 1 mm to 1 cm in diameter. Also there are more than 30000 objects in space that can be tracked.
What is kessler syndrome:
When a collision happens to take place between 2 satellites like the one that happened in 2009, it gets to form a chain reaction. An American commercial satellite collided with inactive Russian communication satellites at an astonishing 35,000km/hr speed. This collision released a large amount of small debris over the size of 1 cm.
Although this did not disrupt other satellites, any such cases in the future will have the potential to completely doom us. When a satellite collides with another object it creates a lot of small debris that will soon strike other satellites.
As there were not many satellites during 2009, this did not pose a threat. But now as more satellites are launched and the space has become more crowded, a similar case will ultimately lead to complete annihilation of all satellites.
This vicious chain reaction is called kessler syndrome. This was the core concept of the Gravity movie. Let us hope that it won't happen in reality.
How are Mega constellations accelerating this problem?
A network or a group of satellites that work together connecting each other is called constellation satellites. Starlink(check out my article on Starlink) is one of the best examples for this. Other missions like Amazon’s Kuiper, UK based OneWeb, Blacksky and planetLab are examples of constellation satellites.
Most of these companies are in an urge to make space internet a profitable business. Starlink alone claims to launch 42,000 satellites and OneWeb says they will launch 1600 satellites. These mega constellations will be placed in the Low Earth Orbit(LEO).
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| Starlink satellites so far launched |
Current situation in LEO couldn't get any worse than this. With starlink dominating the entire LEO there is hardly any space over there. These mega constellation projects have accelerated the accumulation of space debris in such a way that the ISS now has a collision rate of 50%. A decade ago it was just 14-15%.
The new Chinese space station named Tiangong has also accused starlink for how crowded the space is. Their space station was in a collision course with starlink satellites 2 times since its operation. Although Starlink didn't officially reply to their accusation, Elon once said that there is much space over there to fit more than a million satellites. This ridiculed me.
Also an analysis says that starlink alone faces 2400 close encounters with other objects in space, out of which 58% are identified objects.
This shows how mega constellations are posing a greater threat to satellites which connect different parts of the world.
How will this doom us?
Humanity has always been dreaming of reaching stars, and we too have made significant progress over the years. But launching rockets is a double edged sword. As we are making more progress in cosmic research by launching a lot of rockets, it has significantly increased the pace of the ever growing space debris problem.
The ISS, the most expensive human asset, is on the verge of being annihilated. And humanity is yet to achieve a lot of its dreams, but this problem will make the space above us completely hostile. If it gets to its worst point, we have to forget about all our ambitions and pack up our things.
Imagine an artificial cloud dominating over you, It could get no more terrible.
How will we be able to alleviate this problem?
The European space agency says that they are tracking over 32000 objects in space, which only include objects that are big enough to be tracked. But if you include all small and tiny junks, there are over 130 million objects in space.
As you have previously read how even the tiniest object could cause serious damage to a spacecraft during a collision, a million useless and threatening objects waiting to destroy its peer satellites above, is astonishing. And Low Earth Orbit is choking and needs immediate help.
So how are we going to do this:
Using nets:
This is similar to catching a fish from the ocean. A satellite will be launched and will be sent near space debris, when it gets close enough the net opens up and catches that satellite. This was in fact successfully achieved in 2018. A satellite named RemoveDEBRIS was able to capture a dead satellite and was able to bring it back to earth. This method is considered to be the most viable one out of all methods ever proposed.
Robotic arms:
This is similar to that of using nets, but instead of deploying nets, this will use robotic arms to catch a space junk. This mission is proposed by ESA and will be performed by 2025.
Harpoon technique:
As you might guess, this method will use a sharp and strong harpoon that will be targeted towards the junk and will be shot. Once the junk is attached to the harpoon it will be brought back to earth. But when shooting the junk, it might damage the target and release a lot of tiny debris into space. This seems to not be a good method.
Burning with lasers:
The other way is to burn the debris with lasers. This will also be effective against small and tiny objects. But this will create dust debris, which won't help to alleviate our current problem.
Electromagnets:
As most of the objects in space are made of metals, you can use electromagnets to push space debris towards earth or even away from us. But this will require a lot of resources and extensive coordination.
Although we seem to have a lot of options and ideas, we are not as effective and aware as we are supposed to be. All these projects are just in the initial stages of development or they are just proposals. But with SpaceX developing a starship which is a completely reusable rocket, and their falcon 9 which is a partially reusable rocket showed us rockets can become more accessible and reusable.
Keeping SpaceX aside there are also other companies that are working towards the concept of reusability. I hope we will soon have a proper solution for this crisis.
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