Orbital Decay: A Hidden Concern for Low Earth Orbit Satellites and Why It Matters

As the global community continues to expand its space endeavors, the need to ensure sustainable space operations has never been more critical. One aspect that often garners attention in discussions about satellite longevity and space debris management is orbital decay. While orbital decay in very low Earth orbits (vLEO) is increasingly becoming a standard practice to ensure safe re-entry, discussions on this issue remain surprisingly limited. This article delves into why orbital decay is a pressing concern for satellites in low Earth orbits (LEO), especially vLEO, and addresses why this topic is not often brought to the forefront of public discourse.

The Mechanism of Orbital Decay

Orbital decay is a naturally occurring process where a satellite in orbit gradually descends towards the Earth. This happens due to the drag caused by atmospheric molecules, particularly in low Earth orbits where the atmosphere is denser. The denser the atmosphere at a given altitude, the more significant the drag, and hence, the greater the rate of orbital decay.

In very low Earth orbits (vLEO), which range from approximately 160 to 2,000 kilometers above the Earth's surface, the atmospheric density is relatively higher than in higher orbits. This means that for satellites in these orbits, orbital decay can be much more rapid. To mitigate the risks associated with the eventual fall of these satellites, they are often equipped with systems that trigger a controlled re-entry, ensuring they burn up harmlessly in the Earth's atmosphere.

Key Benefits of Orbital Decay

There are several compelling benefits to implementing orbital decay for satellites in low Earth orbits:

Safeguarding Earth's Atmosphere: Controlled re-entry prevents satellites from potentially becoming space debris, which can pose significant risks to other operational satellites, including those at higher orbits. This is particularly crucial as the threat of space debris is increasingly recognized as a growing problem. Ethical Responsibility: Ensuring that satellites are returned to Earth in a controlled manner aligns with ethical considerations and the principles of sustainable space operations. It reflects a commitment to responsible stewardship of space, where space operations do not compromise the integrity and safety of Earth and its environment. Economical Efficiency: Designing satellites to have a planned end to life can also reduce economic costs. By accounting for the need for re-entry, manufacturers can design more cost-effective satellites that do not need to carry additional fuel for potential deorbit maneuvers, potentially lowering operational and maintenance costs.

Why Is Orbital Decay Not Often Discussed?

Despite its importance, discussions about orbital decay for satellites in low Earth orbits are often overshadowed by other topics. Several factors contribute to this phenomenon:

Limited Public Awareness: The complexities and nuances of how satellites operate in space are not always readily understandable to the general public. As such, discussions on technical aspects like orbital decay tend to be technical and therefore not widely covered in mainstream media. Focus on Other Issues: Discussions in the sphere of space exploration and satellite technology often gravitate towards more visible or trending issues like launching new satellites, innovating satellite technologies, or exploring deeper space. Issues related to orbital decay are less likely to gain traction in such a context. Lack of Reporting Mechanisms: There are currently limited reporting mechanisms and transparency in how often satellites undergo orbital decay. This lack of data makes it challenging for interested parties, including the public, to engage with the issue.

Conclusion

Orbital decay is not just a technical necessity for satellites in low Earth orbits; it is also a fundamental aspect of ensuring the sustainability and safety of our use of space. While the discussions surrounding it lag behind other space-related topics, the importance of this issue cannot be understated. As we continue to expand our space activities, it is crucial that we also prioritize discussions and technologies that address the challenges of orbital decay to protect our planet and the vast, complex space environment we share.

The path to a safer and more sustainable space future requires a collective effort. As stakeholders in the space community, it is important to advocate for transparent and proactive approaches to orbital decay to safeguard our shared space for generations to come.