Britain’s weather-monitoring satellite Aeolus is set to make an unexpected return to Earth today in an unprecedented space mission. The satellite was originally designed to return naturally through the atmosphere, but has now run out of fuel The 1,360kg spacecraft, which has been in orbit since 2018, will probably burn up as it passes through the atmosphere and it is hoped it will eventually fall into the depths of the Atlantic Ocean.
Aeolus made history as the first spacecraft to measure Earth’s winds from space. However, after the satellite ran out of fuel earlier this month, it began its gradual descent toward Earth. Such a unique method of re-entry has never been used before, making it a milestone in the history of spaceflight. Holger Kragh, head of the European Space Agency’s (ESA) Space Debris Office, noted the novelty of the situation at the press briefing. He stated, “There are really no similar examples in the history of spaceflight. As far as we know, this is the first such case of re-entry.”
During the press conference, it was suggested that about 80% of Aeolus will be destroyed during re-entry. The remaining 20% is expected to fall into the Atlantic Ocean and sink quickly, leaving no opportunity for recovery. Simonetta Cheli, ESA’s director of Earth Observations, called the satellite a “real success story” as it has an estimated lifetime of more than three years. The results of the mission are expected to be a turning point in the management of end-of-life spacecraft, as there are currently about 2,000 of the approximately 10,000 spacecraft in space that are out of service.
Holger Krag emphasized the need for global cooperation in ensuring the sustainability of space activities. He stated, “Space sustainability must be a global challenge and we must significantly improve the way we design and operate spacecraft today.” ESA aims to achieve “debris-neutral” launches by 2030, requiring the return of all objects placed in space at the end of their mission.
To minimize the risk of fragments falling to the ground as Aeolus enters the atmosphere, the spacecraft’s onboard propulsion system is used for controlled descent. This reduces the probability of dangerous debris hitting populated areas by a factor of three compared to natural re-entry.
As the “impossible satellite” makes its final descent to Earth, scientists and experts are closely monitoring its trajectory. The uniqueness of this mission and the lessons learned from it will undoubtedly shape future endeavors in space exploration and contribute to efforts to create a sustainable and debris-free space environment.
