Strategies to Mitigate Space Debris and Orbital Junk

Mitigating the problem of space debris and orbital junk is a paramount concern for the future of space exploration and satellite operations. While we currently lack the capability to clean up existing space debris, there are several strategies that can be implemented to significantly reduce the amount of debris generated. These strategies range from natural decay to careful planning of orbits and mission designs.

Natural Orbital Decay and the Atmosphere's Role

One of the most natural and effective ways to deal with space debris is through the process of orbital decay. Objects in low Earth orbit (LEO) must contend with the very thin atmosphere, which can gradually slow the satellite to the point of re-entry and subsequent burn-up into the atmosphere. For example, Sputnik only lasted approximately three months in orbit before it burned up upon re-entry, and similarly, the Starlink satellites are anticipated to remain in orbit for around five years before their orbits naturally degrade and they fall back to Earth.

Approximately 65 of our satellites fall into the category of longer-lasting orbits, typically burning up in the atmosphere after several decades or even up to a few centuries, depending on their altitude. However, for debris in orbits higher than these, such as geostationary orbits (GEOs), the situation is more critical.

Mitigating Geostationary Orbit Debris

The geostationary orbit (GEO) at an altitude of roughly 35,786 kilometers above the Earth's equator poses a significant challenge due to the high concentration of satellites and the fact that these orbits are inherently stable, meaning that without deliberate intervention, these satellites would never return to Earth on their own.

To address this, there are several strategies being employed. Firstly, adequate fuel resourcing can be ensured to allow the satellite to re-orientate and use atmospheric drag to re-enter the Earth's atmosphere. This minimizes the amount of redundant material left in orbit. If this is not feasible, designated graveyard orbits are established to keep aging or decommissioned satellites out of the critical LEO and MEO regions.

Proactive Management of Debris Generation

In addition to managing existing debris, proactive measures are taken to minimize the creation of new space junk. This includes careful planning of mission designs and the disposal of spent rocket stages and other objects. By planning the disposal of spent rocket stages and other objects in low orbits or into the atmosphere, the number of additional objects orbiting the Earth is kept to a minimum.

During mission planning, explosive detachment bolts and other objects are managed to ensure that they either re-enter the Earth's atmosphere or remain in stable, non-interfering orbits. This proactive approach helps to avoid creating additional debris that can threaten operational satellites and other space assets.

The Future of Space Debris Mitigation

It is also important to recognize that while the concept of Kesler syndrome, which focuses on the exponential growth of space debris, may sometimes paint a pessimistic picture, the reality is more nuanced. By following these best practices and continuing to innovate, we have the tools and knowledge to mitigate the risks associated with space debris effectively.

Ultimately, the strategies mentioned above, combined with ongoing technological advancements and international cooperation, offer a robust solution to the challenge of space debris and orbital junk. While it is a long-term effort, the proactive measures taken today will ensure a safer and more sustainable future for our increasingly crowded space environment.