[UPDATED] ESA’s Cluster Mission Concludes with the First-Ever Controlled Satellite Reentry

The European Space Agency (ESA) is gearing up for a rare study of a live satellite reentry, which is set to take place in September. The focus is on one of the four satellites from the ESA’s Cluster constellation, launched in 2000, to investigate solar winds and their effects on Earth’s atmosphere. 

The satellite, named Salsa, will retire and reenter Earth’s atmosphere on 8 September, burning up as it descends over the South Pacific Ocean.

Update: 9 September

On the 8th of September, the first satellite in ESA’s Cluster quartet safely came back down to Earth in a world-first “targeted reentry”, marking a brilliant end to this remarkable mission. The spacecraft, dubbed “Salsa” (Cluster 2), reentered Earth’s atmosphere at 18:48 UTC over a remote stretch of the South Pacific Ocean. This location was carefully chosen to minimize any risk of fragments reaching populated areas.

The Last Dance of Salsa Satellite And Epic Reentry

The ESA will deploy a plane equipped with over 20 scientific instruments and a team of scientists to gather data on the reentry process. The mission aims to capture rare data on how and when a satellite disintegrates during reentry, which could help improve future satellite safety measures and sustainability. 

Observations will include tracking the satellite’s fiery descent, potential explosions, and any debris that survives reentry.

Implications for SpaceX’s Starlink Network

This research is particularly relevant for SpaceX’s Starlink, which has launched nearly 7,000 satellites into orbit. While Starlink satellites are designed to burn up completely during reentry, concerns remain about the risks of falling debris and potential chemical emissions that could affect the ozone layer. 

In 2022, the ESA estimated a minor, short-term impact on the ozone from a single spacecraft’s demise but stressed the need for further data to improve these assessments.

Future Plans for Satellite Reentry Studies

Following the observation of Salsa’s reentry, the ESA plans to track the reentry of the remaining three satellites from the Cluster constellation, set to return to Earth in 2025 and 2026. This will allow scientists to conduct a repeatable experiment, providing further insights into the satellite reentry process and refining predictive models for future space missions.