As satellites near the end of their operational life, they face a fate shared by many – re-entry into Earth’s atmosphere. While most satellites burn up during this process, heavy components like reaction wheels can survive and pose a potential hazard. Engineers are keen on addressing this issue to ensure safety.

Satellite debris falling to Earth is a concerning possibility, although the likelihood of it causing harm to populated areas is low. However, with a continuously growing number of satellites in orbit, the risk of debris impacting inhabited regions cannot be ignored.

One notable incident occurred in February 2024 when the ESA’s European Remote Sensing 2 (ERS2) satellite re-entered Earth’s atmosphere. Despite tracking the satellite’s descent and deeming it non-threatening, the ESA acknowledged that such events occur frequently, with objects similar in mass to ERS2 entering Earth’s atmosphere every one to two weeks.

While statistics may suggest a minimal risk to individuals, the reality is that the threat remains. In past instances, like a 1997 incident in Oklahoma where a piece of mesh from a rocket struck a person, the potential dangers have been evident. Additionally, heavy satellite components such as reaction wheels can pose a significant hazard due to their resilience during re-entry.

Reaction wheels play a critical role in satellite control, offering precise maneuvering capabilities without the need for propulsion systems. However, their substantial size and mass increase the risk of survival during re-entry. To mitigate this danger, ESA engineers are developing reaction wheels designed to disintegrate upon re-entry.

Testing these innovative wheels in a plasma wind tunnel at the University of Stuttgart Institute of Space Systems, engineers aim to simulate the extreme conditions of atmospheric re-entry. This proactive approach aligns with ESA’s Clean Space initiative, which focuses on ensuring the complete disintegration of satellites to prevent debris hazards.

At a recent Space Mechanisms Workshop, ESA engineers showcased efforts to comply with Space Debris Mitigation requirements, emphasizing the urgency in adapting satellite technologies to reduce risks to ground infrastructure. The ESA’s Design for Demise program aims to address debris concerns, including active debris removal strategies to clear defunct satellites from Low Earth Orbit.

With the increasing presence of satellites in space, the need for compliant and safe satellite systems is paramount. ESA engineers stress the importance of industry collaboration to meet evolving debris mitigation regulations and ensure the safety of space operations.

In conclusion, as space exploration advances, it is imperative to address the potential risks associated with satellite re-entry. By implementing innovative technologies and proactive measures, engineers strive to enhance safety standards and minimize the impact of space debris on Earth.