Five Ways to Clean up Space debris - VastlyCurious

    Space Travel is the existing and challenging adventure, humanity has ever done, but the problem of space debris might just put an end to it. Over the last few decades, the space debris problem has become a headache for Space Agencies. Most of the space debris is 2000 kilometres above the surface of the Earth and that region is not fully crowded with space junk. If the idea of a debris belt becomes a reality, no other space missions would be possible and even the observation of the cosmos will become a tough job. So what are the ways to clean up the space? Is avoiding the Kessler syndrome even possible?

Prediction of the future of Earth's orbit with Space Debris. source: ESA

    We don't have a proper answer to solve the problem of space debris, but that should stop us from finding the solution to the space debris problem. Countries found out about the seriousness of this problem when the effects of Kesseler syndrome were understood. Now every satellite launched into space has to be destroyed 25 after its mission period is over. But we were already late by then, because we had already produced more space junks by the time we found out about the effects of space debris.

Using Lasers

    Every mad scientist's grand idea is to use a laser to clean up the space debris. The larger satellites could be ablated by the lasers or they could be put down to a safer orbit by the ground-based laser systems. But the ground-based laser systems are not considered idle to eliminate the space debris as most of the space junks have a radius of about 1 centimeter. Focusing the intense laser beam on such a small object is a tough job to do and it requires immense accuracy. So the Space-based laser station is preferred for this job of eliminating the space debris threat.

    The space-based laser station doesn't require this level of accuracy and it could be used to push the debris into the upper atmosphere of the Earth where it could burn itself. The Space debris could be easily tracked by the infrared systems in the space probe and the power required for the system could be collected from the sun via the solar arrays. But nations might get worried about the idea of countries having a laser ground station, which out potentially knock out their own satellites. 

Using Satellite Nets

Collecting the Space Debris using Nets. Source: ESA

    The simple idea of capturing the space debris via the help of nets might just be effective. The RemoveDebris satellite was launched and deployed into orbit in September 2018, which captured the target junk with its net system. The RemoveDebris had an inbuilt camera and LIDAR systems which could help us map the trajectory of the debris and navigate towards it. They would also have thrusters to boost their speed to capture the high-speed debris. This experiment phase proved to be effective for capturing the junks. After capturing the space junks, the debris could be taken to lower orbit and it would be burnt in the upper atmosphere. 

Using Solar Sails

    

    The satellites and spacecrafts which are being launched into space now have an inbuilt solar sail which at the end of their missions will be deployed and the satellites would be taken to the upper atmosphere. But the problem is we already have enormous space debris around our low earth orbit. We could use the same technique to bring down the debris into the upper atmosphere where it will get burned down. We could attach a Solar sail to an already dead satellite floating in the orbit and powered by the solar arrays, it will take the dead satellite to the atmosphere where it will be incinerated. The carbon-based solar sails are now used in the upcoming missions, which uses drag created by the sail to take down the satellites.

Using Magnets

    

    There is so much space debris in the low orbit of the Earth, which is of a radius of just 1 centimetre. They might cause great damage to the satellites in space as they travel at a high speed and so even the smaller debris might destroy the entire satellite. Using magnets is a good way to capture this small debris. The small particles which are magnetic could be easily retrieved by this technique. Although it requires accuracy and precision to pull off this mission.

    The Japanese Space company Astroscale has come forward to clean up the space debris using magnets. A smaller satellite with a magnetic plate is to be deployed into orbit by the Russian Soyuz rocket to capture the dead satellite. This mission doesn't even require a human to operate as it is fully autonomous. This project now plans to capture only one dead satellite, but If this mission proved to be successful, we could launch more satellites with magnetic power to capture the debris and take the debris into the atmosphere where it will be burnt. 

Using Slingshot

    Using the Slingshot to pull the dead satellite into the upper atmosphere might be the efficient way to do it as it doesn't require any fuel. As the slingshot continuously tries to pull and push the satellites into the atmosphere or to outer space, the angular momentum is restored and a limited amount of fuel is only required. It will economically feasible as it doesn't require any large amount of fuel to operate because of the momentum generated by pulling the dead satellite it can slingshot other satellites. The operating period of this Slingshot is also high compared to other projects, but this project is not yet tested in space.

    Cleaning up the space debris is an arduous task and it requires the cooperation of all the governments and private agencies. If we didn't clean the space junks, the Kessler syndrome might become a reality and Earth's orbit will become a dangerous place. If these missions fails, then the idea of colonizing other planets might get delayed and we might end up on Earth. So with these missions, the hope of cleaning the space debris lives on!