We are continuously progressing in space science. Space has lots of mysterious bodies. Today, many countries are planning missions in space. The world is trying to colonize space. This all seems interesting until space debris arrives!
There are many issues in space voyaging. However, the main problem in space voyaging or exploration is space debris.
So, today our topic of interest is space debris and the various ways to clean it. But first…
1. What Is Space Debris
There are many small dots in a satellite image of the Earth. The dots are chunky space debris. Humans already polluted the Earth’s natural resources. Now, humans are polluting beyond the horizon. Space debris is the result of space pollution.
Space debris is a vital issue that we overlooked for several years. It is a collection of useless artificial objects. The objects are broken parts of artificial satellites. It may be empty rockets or pieces of metal. Also, the deactivated satellites become space debris.
Space debris is trash lying in space, that is increasing in its size each passing day. Space debris is not just about satellites and rockets. Astronauts leave their tools while carrying out missions in outer space.
Further, the collision of space debris creates more minute parts of space debris, and the smaller the size of space debris, the greater the speed it acquires. These high-speed objects may collide with functional satellites and make them non-functional.
Space junk is an extreme threat to us. It may damage the whole space. In the technology race, people are barely giving thought to sustainability in space. But now people are aware of the necessity to clean up junk.
For cleaning space debris, tracking it is important. So, let’s see how we will track the space debris.
2. Tracking Space Debris
Due to the space debris, the lower earth orbits are more crowded than before. Thousands of objects are flying there at high speed. There are tiny particles too. These particles are hard to remove completely.
Today, Privateer a space startup is doing the tracking bit for thousands of pieces of space debris in real time. This is for stopping explosive collisions from happening. Their competitors, LEOLABS provide similar debris tracking systems.
Not only are large pieces a threat to us, but smaller pieces are also dangerous. So, the researchers also have to detect the smaller pieces. However, the detection of these tiny particles is not easy.
So, now we know what space debris is and how to track it. Also, we are taking small steps to clear space debris. Let us discuss the ways to clean up space debris.
3. Cleaning Up Space Debris
Space debris is like plastic trash in oceans. As plastic trash is threatening the earth, space debris is also hazardous for space.
To physically clean up the space debris, it has to be deorbited. It means grabbing it and pushing it down to earth’s atmosphere. Here most of the things will burn up while falling. This is due to friction. The debris will end up like a shooting star.
But this is not a cheap operation. Space debris removal missions will cost millions of dollars. Fortunately, many companies are taking part in cleaning up the debris.
3.1 Different Missions To Cleanup Space Debris
In front of the satellite, there will be a grappling system. This grappling system will pick out the larger pieces of debris. It will work on catching space debris instead of colliding with them.
Once the debris is caught, it will be stabilized and slowed down by the system. Once stabilized, it will be sent back into the Earth’s atmosphere.
But it won’t be sent back to any random point in the atmosphere, but to Nemo. Nemo is the farthest point from land in the South Pacific Ocean. So, the reintroduced object will be burnt at this point.
However, these projects are costly. So, many companies are working on creating low-budget projects to remove space junk.
Another mission to clear space debris is RemoveDebris. In this mission, a spider-like net will be floating in space. In this net, part of the debris will get entangled.
However, this mission was just tried once. But the budget of the mission was also very high.
The Japan-based startup Astroscale is hoping to cut out costs by considering the process right from the very beginning.
Astroscale will be placing a docking plate, which is lightweight and efficient.
The future satellite should be easily docked, so that it can help to reduce future debris. After launching the satellite, it’s not that we just say goodbye to the satellite and never see it again. Instead, we should be maintaining, repairing, and removing it.
3.2 Rules For Controlling Space Debris
FCC recently brought in a new five-year rule for satellites. The rule is that the satellites should be deorbited after completing their missions.
The space guidelines are hard to enforce. Because no police in space can find who breaks the rule and fine them.
3.3 Ways To Grab Space Debris
We have created a vast network of satellites that are vital to many terrestrial technologies. But all this resulted in space debris.
This debris could be the biggest obstacle in future space missions. So, here we will be discussing the ways to capture space debris.
3.3.1 Claw Capture
A Swiss-based company known as Clearspace is working on claw capture technology. It is building a chemically powered rocket spacecraft that will feature a four-armed claw.
The claw will first match the orbiting trajectory of the target before extending its arm. This mission will most probably be launched by 2025 and is aimed to target large debris objects.
The claw will further turn them into small pieces once captured, which will further prevent the creation and collision of more space debris.
However, the mechanical capture of the target requires careful matching of the velocities. In this claw system, we can set the upper and lower limits of the size of objects.
3.3.2 Magnetic Capture
To take things up a notch, magnetic dugout systems are being planned to launch too. One such system is currently being worked on by a Japanese company known as Astroscale.
Capture is performed by matching the trajectory of a satellite or debris.
On 25 August 2021, the company successfully performed a trial of a magnetic capture system. The test successfully demonstrated the capability of capturing the client object.
The company proposes that we can pre-engineer the satellite with a lightweight magnetic docking plate. This will make the process more reliable.
3.3.3 Surrey Satellite Technology
Surrey satellite technology is a RemoveDebris project conducted by multiple companies in collaboration. The system is inspired by Roman gladiators. It is designed with Airbus features, which will have a tethered harpoon and a weighted net casting system.
In 2019, RemoveDebris was successfully tested. Using their net systems they captured a targeted CubAsat. CubeSat is a small type of satellite.
So, the system tracked the CubeSat. And once it was in the 7-meter range it was captured in the space net.
The system is capable of capturing very large pieces. The second trial held for this system also gave different angles for clearing the debris.
3.3.4 Laser Broom
Electro-orbit system i.e. EOS is an Australian company with experience in developing laser systems for use in aviation and defense industries.
In space stations, engineers use high-energy laser pulse radiation to prevent the collision of space stations or other high-value space assets with smaller debris particles, ranging from 1cm to 10 cm in size.
The laser radiation heats the debris. The heating provides the impulse to the debris particle. The proper direction of the impulse deflects the object’s trajectory away from the satellite.
The idea is that it will scan across the sky systematically. This will remove the debris from the trajectory of high-value space assets. Most of the research concentrates on the ground-based laser system.
However, the ground-based laser system has to face atmospheric distortions. So, these will make it difficult to track the smaller objects. However, we can use this system to quickly target many pieces of debris. So, we can use these systems more effectively than other ones.
4. Scientists Plan To Clean Space Junk
The space is dangerously crowded and filled with junk. Especially near the earth, it is more crowded. There are more than 4500 satellites in the Earth’s orbit. As time goes on, the space will be more crowded. There are not just working satellites. Mostly the satellites are not in use.
Now, we can track space debris. Space debris smaller than 1cm in size is difficult to track. Also, their speed is quite high. So, it’s really important to develop the technology to detect smaller space debris.
Detection is not the only step. We discussed various ways to grab space debris above. Scientists are working on them to make them more advanced.
Scientists are predicting if the space debris is not controlled it will create the Kesslers syndrome.
4.1 Kessler Syndrome
Currently, the problem of space debris is manageable. However, some scientists predict that shortly, the situation will worsen.
When there is too much debris in space, it might start crashing into itself. This would result in the creation of more space debris.
This will continue to create space junk. Eventually, it will block all the ways of going into space from Earth. There will be a prison of debris.
This is the Kessler syndrome. Even though it’s not the current problem, in the future it will be. So, solving this problem is very crucial. It is a huge challenge for humanity.
5. The Power Of Space Debris
With the increasing rate of launches, space is getting busy. There are around 10,000 tons of space debris. We know that space debris can damage spacecraft. But, how we shield the damage of the International Space Station from space debris?
ISS is constantly in the firing line of space debris. It’s not easy to shield something Larger like the International Space Station.
Instead of using thick plating, The ISS uses a Whipple shield.
5.1 Whipple Shield
Whipple shield consists of a thin outer wall. It has a small gap and a thick inner wall. The outer wall shatters the projectile into finer pieces. So, the kinetic energy is spread out into many smaller impacts on the inner wall.
In some areas of the shield, the space between the two walls is stuffed with high-impact material. The material may be kevlar or aluminum oxide.
On the ISS there are many different shield configurations as balance needs. The balance between weight and amount of protection is considered while making the shield. But after creating the shield it is important to test it.
5.2 Testing The Whipple Shield
For testing the shield, it needs high-velocity particles. So, the explosive charge creates such particles. This charge moves the piston and compresses the sealed chamber of gases. At the end of the chamber, there is the thin bursting disk.
This disk bursts with the specific pressure. Once it bursts the rapid expansion of gas occurs. This expansion accelerates the projectile up to the orbital velocities. So, this artificial particle mimics the small particle of space debris.
5.3 Whipple Shield To Protect From Space Debris
Moving back to the topic, when the high-speed debris particle collides with the shield the particle quicklyde-acceleratess.
So, this compresses both the debris particle and the shield. As a result pressure on both objects increases. Then the temperature gets enough to melt the debris particle.
The compression sends a shock wave through the debris particle with the strength of tearing apart the material.
All of this happens very quickly. So, the scientists in the ISS would never see happening it.
5.4 Advancements in Whipple Shield
The current technology uses aluminum oxide or kevlar between the walls. But in the future, it is possible to replace these materials with new materials. The new material will perform something called Rapid Puncture-initiated Healing.
This involves filling the space between the two walls with liquid. So, as debris passes through the shield at high velocity, the heat and friction will stimulate the liquid to flow into the hole and plug it as it hardens.
Another test involved liquid reacting with oxygen. This sealed the hole in less than a second.
The improvements in the shield are necessary to prevent space debris from damaging the missions. The lighter shields that are easier to fix have great significance. Also, these shields will be crucial for long-haul trips like Mars missions and beyond.
Not just the Whipple shield, but there are many plans to avoid the danger of space debris. So, until we find the perfect way to remove space debris, ultimately we have to rely on these kinds of shields.
Till now, we discussed space debris and its impacts. Also, we discussed ways to clean it up and avoid it. Cleaning the space debris is very crucial. For future generations, we should not leave the debris that we created.
This will be the hurdle for future generations to go out of the earth. So, while progressing we have to manage the waste created by humans.
Space debris if not controlled, would be the biggest threat for us. It will suffocate the earth completely. Also will block the way to exploring outer space. So, controlling space debris is a need of time.
Late is better than never! Thankfully, the scientific world is now aware of cleaning space debris. Scientists are working hard to create plans to control space debris. Various companies are taking part in the cleanup of space debris. So, hopefully, very soon we will be able to control the space debris.
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