Managing Space Debris: Clean-Up Strategies and Technological Challenges

In 2013's Gravity, the film depicted the dangerous fragmentation of assets in Low Earth Orbit (LEO). The reality of space debris, while less dramatic, is significant. But how long would it take to clean up LEO and geostationary satellites from this debris?

Current Status and Projections

A 2011 Arecibo Observatory study estimated that there are approximately one million objects larger than 2 millimeters in LEO. However, these objects are too small to be visible from Earth-based observatories. Current technology and resources allow us to discover only a fraction of this debris. Finding and cleaning up every piece is practically impossible.

Cleaning Up: A Long-term Process

According to Kevin Rome, the process of cleaning up space debris is a long-term endeavor. Based on the current rate of satellite launches, the number of LEO satellites could double, triple, or increase even further. We need to take this issue seriously and consider solutions such as satellite traffic lanes. With lower relative velocities, the debris would be confined to smaller areas, streamlining the cleanup process.

Despite much talk about space debris, and some funds dedicated to research, the issue hasn't garnered the necessary urgency. However, the evolving nature of technology and the collective focus of the scientific community can lead to the development and deployment of tools necessary to manage space debris. As with any persistent problem (like trash on the side of the road), it is an ongoing process of cleanup.

Technological Challenges and Solutions

Currently, we do not have the technology to capture and clean up large wrecks like Envisat. The issue is exacerbated by the fact that most of the small debris does not even show up on radar. Even if we had the technology, much of this debris will take years, even decades, to re-enter the Earth's atmosphere.

Take Envisat, for example. Projected to stay in orbit for 150 years, it is currently at an altitude of about 770 km. Debris from geostationary satellites could remain in orbit for even longer periods. To replace these satellites, we must first build and test new ones, a process that takes months or years, followed by additional months of ground tests. Creating the launchers required for this process also takes considerable time.

Given these time constraints, one proposed solution is to build more com-blimbs (communications airships). Com-blimps, built for hydrogen propulsion, offer a viable alternative to traditional launchers. Hydrogen is a potential solution to the looming helium shortage, which could become more expensive.

Conclusion

Managing space debris is a multifaceted challenge that requires long-term planning and technological innovation. While there is much work to be done, the possibilities for a cleaner, safer space environment are promising. By focusing on clean-up strategies and enhancing our technological capabilities, we can mitigate the risks posed by space debris.