Space Junk

In 2009, a Russian military satellite collided with an American communication satellite. Each satellite was traveling 36,000 kilometers per hour. The aftermath created thousands of pieces of debris. This was the biggest satellite collision in history and an eye-opening warning about the worsening crisis of space.

This incident describes the growing problem of space debris, which poses serious risks to satellites, spacecraft, and even astronauts in orbit. With millions of human-made objects circling the Earth, collisions like the one can generate even more debris, exacerbating the issue.

Cleaning up space junk is a complex task. Various proposals have been made, including using robotic arms or nets to capture debris, deploying spacecraft with ion thrusters to deorbit debris, or even using lasers to nudge debris into lower orbits where it will eventually burn up in the Earth's atmosphere. However, implementing these solutions requires significant technological advancement, international cooperation, and financial investment.

Navigating through space debris is like driving through a cluttered highway filled with abandoned vehicles—each one posing a potential threat to navigation and safety.

The accumulation of space junk, dead satellites, and rocket parts in Earth's orbit presents a significant challenge to current and future space activities. With each new satellite launch or space mission, the risk of collision increases, potentially leading to catastrophic consequences such as the loss of critical infrastructure or even hindering future access to space.

The potential implications for space exploration are profound. If we don't address the issue of space debris, we may reach a point where it becomes too risky or costly to launch new satellites or build space stations. This could severely hamper scientific research, telecommunications, Earth observation, and other essential functions that rely on space-based assets.

To avoid such a scenario, we need to actively remove existing debris from orbit, but it’s not that easy.

A team of researchers in Switzerland have developed an enormous claw to grab the space junk and bring it back to earth. The solution is called ClearSpace.

The accumulation of space debris can be attributed to several factors that have evolved over time since the launch of the first satellite in 1957.

Satellite proliferation: Since the launch of Sputnik 1, the first artificial satellite, there has been a significant increase in the number of satellites launched into Earth's orbit. Initially, satellites were primarily launched by governments for scientific and military purposes. However, with advancements in technology and decreasing costs, the satellite industry has expanded rapidly. Today, satellites are used for telecommunications, navigation, weather forecasting, Earth observation, and a variety of other applications, leading to a proliferation of objects in orbit.

Fragmentation events: Spacecraft collisions, explosions, and other events can generate fragments of debris. These fragmentation events can occur accidentally, such as the 2009 collision between the Russian military satellite and the American communication satellite you mentioned earlier, or intentionally, such as anti-satellite missile tests conducted by some countries. Each fragmentation event adds to the population of space debris, creating more hazards in orbit.

Rocket stages and spent satellites: In addition to operational satellites, rocket stages and spent satellite components also contribute to space debris. After delivering their payloads into orbit, rocket stages are often left to drift in space or are intentionally deorbited, adding to the debris population. Similarly, satellites that reach the end of their operational life may remain in orbit as "dead" objects, further cluttering Earth's orbital environment.

Lack of debris mitigation measures: Historically, many satellites were launched without sufficient consideration for the long-term implications of space debris. As a result, there was a lack of standardized practices for mitigating the generation of new debris, such as deorbiting satellites at the end of their operational life or designing satellites to minimize the risk of fragmentation.

Engineers at ClearSpace Headquarters are working to remove debris from the “Low Earth Orbit” A Low Earth Orbit, is an orbit that is close to the Earth’ surface. It ranges from 160 - 2000 kilometers above the earth surface. Their closer proximity to Earth offers benefits such as higher resolution imaging and easier access for manned missions like the International Space Station (ISS). Additionally, the abundance of available orbital paths allows for greater flexibility in satellite deployment.

The fast-moving nature of LEO satellites presents challenges for tasks like telecommunications, as they quickly traverse the sky, requiring ground stations to track them continuously. LEO satellites play a crucial role in various applications such as Earth observation, environmental monitoring, scientific research, and space exploration. Despite their challenges, the advantages of LEO make it a popular choice for satellite deployment and further exploration of space.

Polar orbits are a type of LEO that do not have to pass the North and South Pole. They are at low altitudes between 200 - 1000 km. Sun-Synchronous Orbit (SSO) is a type of polar orbit. These satellites are synchronized to be in the same fixed position relative to the Sun. The satellite always visits the same spot at the same local time.

Polar orbits are crowded because that positioning lets satellites get a complete picture of Earth underneath them. An object's orbital altitude determines how long an object stays in orbit. Lower orbits decay more quickly.

When satellites are launched below 500 kilometers, there is still enough atmosphere there that if they aren't operational anymore, they will naturally fall back down into the earth, into the atmosphere. This will happen every few months or years.

For an object to stay in low earth orbit for many years, like the ISS, it must regularly boost itself up to counteract this atmospheric drag. The higher an object is in orbit, the weaker gravity's grip and the longer it will stay in space. If you launch them at 600 kilometers ,the object will stay there for up to ten years. The ClearSpace Mission aims to collect a satellite fragment currently orbiting near this altitude. Higher orbital altitudes, like geosynchronous orbits, can possibly stay in orbit indefinitely.

Even the smallest space junk at orbital velocities can do major damage to active satellites, and space stations. The more crowded space gets, the more likely that objects will crash into each other creating a domino effect of space junk.

When two objects collide in a crowded orbit, they create hundreds or even thousands of new pieces; and when those collide, they break into even smaller pieces.

There's already so much junk and space. The International Space Station has to take evasive maneuvers to avoid it multiple times a year. The ClearSpace claw robot could be a very handy solution to this problem.

One is a space robot designed to grab a nose cone that's left over from the satellite deployment process. It’s similar to the claw game at the arcade; however being in space makes much harder.

ClearSpace is training their robot to be even better than human hands or arcade claw game hands. ClearSpace is using machines to cleanup, find and grab its space junk target.

Without the help of human intervention. We're trying to generate realistic images of the target that are found in space.

The main source of light that we have is then the sun, which creates very high contrast scenes. The ClearSpace will have an array of cameras that lets it see its target. Depending on the position of the sun relative to the target object makes it difficult to see the target.

Our eyes can intuitively interpret things like perspective and illumination, computer vision has to be trained to do that. We can see almost the entirety of the target. We can easily move to determine and see which features are where. Move to the right or move to the left.

Training the robot to see is just the first problem. Then researchers also have to figure out how to grab the nose cone without it. Researchers considered using nets or mechanical fingers, but they landed on tentacles. When we catch a ball with our fingers, we start closing our fingers around the ball so that we have a firm grip. The same is true for ClearSpace. The arms need to come in closer to grip the objects in a secured manner.

In order to make sure ClearSpace doesn't crash, the robot and the trash have to move at the exact same speed before it deploys the tentacles. Space junk is also spinning. ClearSpace will have to match both velocity and rotation if it wants to capture its target without careening off and becoming space junk itself.

Matching the speed and movement of an object seems like no big deal to us because we have eyes and brains that evolve to track and process movement. Robots don't have that.

Other research teams are trying to solve this problem too. With magnetically docking repair bots to fix broken satellites, even refuel them to prolong their mission life. Cleaning up space junk won't be enough on its own.

We'll also need to stop putting new space junk into orbit and planning the full lifespan of every object we put into space. A difficult challenge considering the treaties Around space launches designate space as a common area under no individual country's law.

Prevention is just as important as cleanup. Space agencies and satellite operators are increasingly implementing measures to mitigate the creation of new debris, such as designing satellites to deorbit themselves at the end of their operational life or using collision avoidance maneuvers to reduce the risk of collisions.

A concerted effort from the global space community, including collaboration between governments, space agencies, private companies, and research institutions. As space becomes increasingly crowded with satellites and other objects, it's crucial to take action to ensure the long-term sustainability of space activities.

By taking proactive steps to address the space debris problem, we can safeguard the future of space exploration and ensure the continued peaceful and sustainable use of outer space.