As many countries around the world celebrate their progressive efforts to reduce plastic pollution by banning single-use plastic bags, a new challenge emerges, and it’s literally out of this world. The problem of space debris has taken center stage, and it’s not just a small issue. Thanks to our brilliant minds, we now have tons of plastic waste orbiting our planet, a problem that’s not only a sight for sore eyes but also has the potential to bring space missions to their knees.

Space debris refers to man-made objects in space that are no longer in use or have lost contact with the ground. This can include spent rocket stages, defunct satellites, fragments from explosions or collisions, and other objects that have been abandoned or lost in space. A significant amount of space debris is situated within low Earth orbit, which is approximately 2,000 km (1,200 miles) from Earth’s surface. Although some debris can also be located in the geostationary orbit, situated 35,786 km (22,236 miles) above the Equator. According to the United States Space Surveillance Network’s data, as of 2021, they have recorded over 15,000 fragments of space debris that are larger than 10 cm (4 inches) across. However, it is believed that there are roughly 200,000 pieces that measure between 1 and 10 cm (0.4 and 4 inches) across, with potentially millions of smaller pieces. The time it takes for space debris to fall back to Earth is based on its altitude, with objects orbiting below 600 km (375 miles) taking several years to re-enter the Earth’s atmosphere, while those above 1,000 km (600 miles) can orbit for centuries.

Plastic, which is ubiquitous in our everyday lives, has become a significant part of space debris. With the advent of technology and the growing use of plastic in various fields, space exploration has seen an increase in plastic waste, which has contributed to the already growing issue of space debris. Plastic waste, when left in space, poses a significant threat to current and future space missions. The plastic waste in space debris takes longer to degrade than on Earth, and its persistence in space can lead to collisions with other man-made objects or even asteroids. Such collisions create more debris, which, in turn, poses a threat to space missions, astronauts, and even satellites that we depend on for communication and weather monitoring. The consequences of space debris and plastics are far-reaching and potentially catastrophic. The International Space Station (ISS), which orbits Earth at approximately 400 km (250 miles) above its surface, has been hit by debris several times, requiring repairs to ensure the safety of the crew. This serves as a stark reminder of the dangers that space debris poses.

 

What is being done ?

The reality is that despite our efforts to address the problem of space debris, we are actually creating more waste than we are able to remove. You don’t have to take my word for it, just take a look at the evidence here:

Although the image shown in the link may exaggerate the size of the space debris, it serves to illustrate the severity of the problem. The challenge we face is that the debris can be as small as a screw, making it nearly impossible to collect and dispose of properly. International cooperation is important in addressing the problem of space debris. The United Nations Committee on the Peaceful Uses of Outer Space (COPUOS) has developed guidelines and recommendations for the mitigation of space debris, and space agencies from different countries are working together to monitor and track debris to minimize the risk of collisions. Here are some strategies being used to address the situation:

• Active debris removal: There are a few companies like Astroscale and Clearspace that are working on developing technologies to capture and remove large pieces of debris from orbit.
• Deorbit sails: NASA has developed a deorbit sail, which is a thin sheet of material that can be attached to a defunct satellite or other large piece of debris to increase atmospheric drag and bring it back to Earth faster.
• RemoveDEBRIS : The RemoveDEBRIS project is a research initiative funded by the European Union to develop and test innovative technologies for removing space debris from orbit. The RemoveDEBRIS spacecraft was launched in 2018 and demonstrated four key technologies for space debris removal: a net to capture debris, a harpoon to pierce and capture debris, a vision-based navigation system to track and approach debris, and a drag sail to de-orbit the spacecraft and any captured debris. The spacecraft successfully captured and deorbited two cubesats during its mission. Here’s a very interesting video to the same :

 

What problem does Plastic pose ?

The ubiquitous presence of plastic waste in our environment is a problem that goes beyond the physical clutter it creates. Even in space, plastic debris poses a significant chemical threat to the atmosphere through a process called photodegradation. When plastic encounters UV radiation from the sun, it undergoes a breakdown process that fragments the polymer chains into smaller and smaller pieces. These fragments can then react with other chemicals in the atmosphere to form new compounds, some of which can be detrimental to human health and the environment.

One example of this is when plastic fragments react with ozone in the atmosphere, producing highly reactive hydroxyl radicals that can contribute to the breakdown of other atmospheric pollutants like methane and carbon monoxide. While these reactions may also produce less harmful compounds, such as organic acids, the overall impact of plastic on the atmosphere remains a significant concern.

In fact, experts such as Ekaterini Kavvada, directorate general of Defence Industry and Space at the European Commission, have raised the alarm about the mass of plastic waste in space. Specifically, the lower orbit of Earth has been likened to a “drifting island of plastic” due to the sheer volume of plastic debris present. This highlights the urgency of addressing the problem of plastic waste, not just on Earth but also in space, to protect our planet and its inhabitants.

 

Innovative Solutions for the Future

These futuristic solutions include projects such as ESA’s e.Deorbit mission, Astroscale’s ELSA-d mission, and JAXA’s KITE project.

• ESA’s e.Deorbit mission: This project aims to capture and remove a large defunct satellite from orbit using a robotic system. The satellite will be captured and then de-orbited into the Earth’s atmosphere, where it will burn up upon re-entry.

• Astroscale’s End-of-Life Services by Astroscale-demonstration (ELSA-d) mission: This project involves deploying a spacecraft that will use a magnetic docking mechanism to remove defunct satellites from orbit. The spacecraft will capture and then de-orbit the satellite, allowing it to burn up upon re-entry.

• Japan Aerospace Exploration Agency’s (JAXA) Kounotori Integrated Tether Experiment (KITE): This project involves using a tether to de-orbit space debris. A small satellite will deploy a 700-meter tether, which will be used to capture and de-orbit space debris.