The Ugly Side of Space Exploration: Space Debris

Growing up, we were always taught that cleanliness is a virtue and to keep our homes and surroundings tidy. Yet, when it comes to caring for our space, we seem to be falling short.

The European Space Agency Space’s (ESA) Debris Office estimates there are about:

130 million space debris ranging from 1mm to 1cm

1,100,000 space debris objects ranging between 1 cm and 10 cm

40,500 space debris objects greater than 10 cm

What’s worse is that the amount of junk only keeps increasing with every rocket or satellite launch. This affects both the satellites and humans in numerous ways.

The Kessler Syndrome

Although the general public is only now beginning to recognize the issue, scientists have been raising concerns since the 1970s.

One of these scientists, Donald J. Kessler, addressed the dangers in his groundbreaking paper, ‘Collision Frequency of Artificial Satellites: The Creation of a Debris Belt.’ Kessler warned that without proper management, space debris could perpetuate an endless cycle of collisions, as the resulting fragments would continue to generate further collisions, even without new satellites being launched.

Kessler wrote, “The probability of collision will increase faster than the ability to remove debris or prevent its creation.” This is known as Kessler Syndrome. He essentially warned that unless measures were taken to reduce debris, space could become a “minefield” for satellites and space missions.

Experts are especially worried about the Low Earth Orbit (LEO), which houses most satellites, as well as human-occupied spacecraft like the International Space Station (ISS). While 1 mm to 1 cm may not seem much, note that debris travels at a significantly high speed, around 7-8 km/s (15,000-18,000 mph), meaning even small fragments can cause significant damage to spacecraft and satellites.

This indirectly affects us back on Earth. Collisions with space debris can damage or destroy satellites, leading to disruptions in communications, navigation, weather forecasting, and other essential services.

Large Debris Even Hit Earth

Not just satellites or astronauts, space debris also poses a threat to us on Earth.

Large space debris, such as defunct satellites or rocket stages, occasionally re-enter Earth’s atmosphere. Most of it burns up during re-entry due to the intense heat generated by friction with the atmosphere. However, some pieces, particularly the denser components (e.g., metal parts or fuel tanks), can survive the re-entry process and fall to Earth.

The first recorded person to be hit by space debris is Lottie Williams. She holds the Guinness World Record for the same. She was walking in a park when a small piece of what was believed to be a Delta II rocket hit her shoulder.

In 2002, a 6-year-old boy, Wu Jie, was the first person to be injured by space debris. A block of aluminum measuring 80x50 cm fell from the sky as he sat under a tree, injuring Wu’s toe and forehead.

Most recently, a metal part of ISS crashed into a Florida home after it was seemingly “dumped.” The homeowner, Mr. Otero, reported, “It almost hit my son. He was two rooms over and heard it all.”

NASA estimates at least one cataloged piece falls back to Earth every day. Although most objects burn up in the atmosphere, threats to humans and buildings remain nevertheless.

Global Effort to Reduce Space Debris

Thankfully, efforts to combat space debris are growing in importance.

Several international space agencies, governments, and private companies are working together to develop strategies to mitigate the problem. These efforts include preventive measures to reduce the creation of new debris, as well as active initiatives focused on removing the debris already in orbit.

Debris Mitigation Guidelines

International bodies like the United Nations (UN) Committee on the Peaceful Uses of Outer Space (COPUOS) and the Inter-Agency Space Debris Coordination Committee (IADC) have developed guidelines aimed at minimizing the creation of new space debris. These guidelines, while voluntary, are widely adopted by space-faring nations and companies.

Key recommendations include post-mission disposal, limiting mission-related objects, and minimizing accidental breakups. Consider it a “Best Practices Guide” for space agencies.

NASA’s Orbital Debris Program Office

NASA’s own Orbital Debris Program Office sets standards for U.S. satellites to minimize debris creation and ensures that new spacecraft are designed to comply with debris mitigation practices.

The ODPO maintains a catalog of known space objects, including debris, to track their orbits and potential collision risks.

ESA’s Space Debris Mitigation Policy

Likewise, The European Space Agency has launched the Space Debris Mitigation Policy, which requires European satellite operators to follow guidelines on debris reduction. This policy aims to ensure the long-term sustainability of space activities by promoting responsible space practices.

Space Surveillance Network (SSN)

Operated by the U.S. Department of Defense, SSN tracks more than 36,000 objects in orbit and provides warnings of potential collisions. This ensures no more unwanted debris is created due to collisions.

SpaceX’s Starship

While still in theoretical stages, SpaceX’s ambitious project, Starship, may help clean existing space debris. Starship’s primary purpose is to provide reusable launch and landing capabilities for large payloads, but its design and capabilities can contribute to debris mitigation efforts in several ways.

SpaceX’s COO, Gwynne Shotwell, was quoted saying, “It’s quite possible that we could leverage Starship to go to some of some of these dead rocket bodies — other people’s rockets, of course — basically, go pick up some of this junk in outer space.”

Conclusion

Just like cleaning homes and Earth, tidying up space is a task humans must embrace. As we expand into space and set up colonies/bases, space debris collection and recycling should be at the heart of such endeavors.

Sources:

First person hit by space junk. (2021, August 10). Guinness World Records. https://www.guinnessworldrecords.com/world-records/114727-first-person-hit-by-space-junk

Kessler, D. J., & Cour‐Palais, B. G. (1978). Collision frequency of artificial satellites: The creation of a debris belt. Journal of Geophysical Research Atmospheres, 83(A6), 2637–2646. https://doi.org/10.1029/ja083ia06p02637

Matza, B. M. (2024, April 16). Nasa says part of International Space Station crashed into Florida home. https://www.bbc.com/news/world-us-canada-68828078

Space Environment Statistics · Space Debris User Portal. (n.d.). SDUP. https://sdup.esoc.esa.int/discosweb/statistics/

UNITED NATIONS. (2010). Space Debris Mitigation Guidelines of the Committee on the Peaceful Uses of Outer Space. In Space Debris Mitigation Guidelines of the Committee on the Peaceful Uses of Outer Space. https://www.unoosa.org/pdf/publications/st_space_49E.pdf

Wall, M. (2020, November 2). SpaceX’s Starship may help clean up space junk. Space.com. https://www.space.com/spacex-starship-space-junk-cleanup