Increasing Space Debris - Are there solutions?

by Kate Green

October 19, 2024

The Disney-Pixar movie WALL-E (2008) offers an interesting, if not entirely realistic, portrayal of Earth's future, including a representation of space debris. While the film primarily focuses on environmental degradation, its depiction of space junk hints at real-world issues related to space debris and human neglect of sustainability.

The real life growing issue of space debris, or space junk, is a significant challenge for the future of space exploration and satellite operations. As more nations and companies launch satellites and missions into Earth's orbit, the risk of collisions and disruptions increases.

Why is Space Debris a Problem?

Space debris includes defunct satellites, spent rocket stages, fragments from collisions, and other non-functional objects in Earth's orbit. These range from large objects to tiny paint flecks, but even small debris traveling at high velocities (up to 28,000 km/h) can cause severe damage.

As of October 2024, over 36,000 pieces of debris larger than 10 cm are tracked, but millions of smaller, untracked particles also pose dangers. Collisions between debris and operational spacecraft could lead to a Kessler syndrome, where the density of objects in low Earth orbit (LEO) reaches a point that leads to cascading collisions, rendering orbits unusable for satellites or space missions, trapping humanity on Earth much like in WALL-E.

Space debris threatens active satellites, the International Space Station (ISS), and future space missions. It also endangers human spaceflight and critical infrastructure like communication and weather satellites.

Proposed Solutions to the Space Debris Problem

Active Debris Removal (ADR)

ADR involves removing large debris objects before they cause collisions. Several concepts are being developed:

• Space tugs: Satellites equipped with robotic arms or nets could capture and deorbit large debris.

• Harpoons and nets: Special satellites can harpoon or net debris, dragging it into Earth's atmosphere to burn up.

• Lasers: Ground-based or satellite-based lasers could "nudge" debris by altering its orbit slightly, causing it to deorbit and burn up in the atmosphere over time.

A real life example is the European Space Agency’s (ESA) ClearSpace-1 mission, planned for 2026, which aims to capture and de-orbit a large piece of space debris (a rocket component) using a robotic arm.

Debris Mitigation

The reduction in the creation of new debris is crucial with mitigation strategies including:

• End-of-life protocols: Satellites should be designed to either deorbit themselves or move to a graveyard orbit at the end of their operational life. This is already a regulatory requirement for some missions.

• Design improvements: Satellites and rockets should minimize the shedding of parts during launch and operations, and be made of materials that degrade more quickly in orbit.

An example of this is the UN’s Outer Space Treaty and Inter-Agency Space Debris Coordination Committee (IADC)  which recommends guidelines for minimizing debris, though enforcement is challenging.

International Cooperation and Policy

• International treaties: Coordinated international policies and agreements will be necessary to enforce space debris regulations, ensuring that all countries follow best practices for debris mitigation and removal.

• Debris-tracking networks: Nations must work together to enhance global tracking systems. This includes sharing data about debris objects and possible collisions.

Organizations like the UN Office for Outer Space Affairs (UNOOSA) work to foster international dialogue on space sustainability - but again, not all countries and private / commercial companies are willing to participate.

Space Traffic Management (STM)

Just as air traffic control manages airplanes, STM aims to manage and monitor objects in space. By tracking large debris, space agencies can prevent collisions and ensure the safety of space missions. However, as the number of objects in orbit grows, this task becomes more challenging, emphasizing the need for active debris removal and better space traffic management.

• Real-time tracking: Enhanced debris tracking and collision-avoidance systems could help prevent potential collisions between satellites and debris.

  
  

• Autonomous systems: AI-powered systems onboard satellites could automatically adjust orbits when on a collision course with debris.

  
  

• Tracking Objects Larger than 10 cm: Pieces of debris larger than 10 cm are considered large enough to be tracked with ground-based radar and optical telescopes. Space agencies such as NASA and ESA (European Space Agency) keep continuous track of these objects. Private organizations like the U.S. Space Surveillance Network (SSN) and LeoLabs also track debris and offer collision avoidance services for satellite operators.

  
  

• Catalogued Objects: There are currently over 36,000 pieces of debris larger than 10 cm orbiting Earth that are being tracked. These include defunct satellites, spent rocket stages, and fragments from collisions or disintegration events.

  
  

• Avoidance Manoeuvres: When larger pieces of tracked debris come close to active satellites or the International Space Station (ISS), operators are alerted and sometimes perform avoidance manoeuvres to prevent collisions.

  
  

• Objects Between 1 and 10 cm: Although objects between 1 and 10 cm are harder to track, they are still dangerous. These are often detected using radar, but their precise orbits may not always be catalogued. The number of objects in this size range is estimated to be much higher, in the hundreds of thousands.

  
  

• Smaller Debris: Even smaller debris (under 1 cm) poses risks, especially to spacecraft and Astronauts, though these are too small to track individually. Shielding techniques are used to protect spacecraft from these tiny, high-velocity objects.

Recycling and Repurposing in Space

• In-orbit recycling: A future possibility could involve missions that collect debris and repurpose materials in space for manufacturing. This would help clear orbits and provide resources for constructing spacecraft or stations without launching materials from Earth.

• On-orbit servicing: Some companies are developing satellites that can extend the life of other satellites by refueling or repairing them, preventing them from becoming debris.

  
  

Another private company example is that of Northrop Grumman’s Mission Extension Vehicle (MEV) that successfully extended the life of a communications satellite, showcasing the potential of on-orbit servicing.

The Path Forward

While Disney's WALL-E is an animated science fiction film, its portrayal of space debris serves as a cautionary tale. It highlights the importance of addressing real-world environmental and space sustainability issues before they spiral out of control. It reflects a growing awareness of the need for responsible space exploration, better debris management, and sustainable living on Earth.

Innovative solutions are being developed with the challenge being implementing these solutions globally and at scale. Active removal efforts combined with strong mitigation policies, technological advances, and international cooperation offer the most promising paths to maintaining a sustainable space environment for future generations.