After 24 years in space, an ESA’s satellite is reentering Earth’s atmosphere today

The recent reentry of the Salsa satellite signals the conclusion of the long-running Cluster mission, which has provided over two decades of valuable data on Earth's magnetic environment. Although the other three satellites in the cluster will cease active observations, researchers anticipate continued discoveries from their existing datasets. Notably, Salsa's reentry represents a pioneering effort in targeted reentry, surpassing previous international practices aimed at reducing space debris. This innovative approach involved careful maneuvering months to years prior to ensure the satellite would reenter over a specific area, allowing for a controlled descent without the need for real-time guidance during reentry. Given its eccentric orbit, Salsa's demise is significant as it marks the first application of targeted reentry for such satellites. While most of its 550 kg mass is expected to disintegrate upon reentry, some fragments may survive the intense conditions. The conclusion of the Cluster mission also provides a unique opportunity to analyze the reentry behaviors of multiple identical satellites under varying circumstances. This data will enhance our understanding of atmospheric reentry dynamics and contribute to the design of future satellites with a focus on eliminating space debris. From a transportation expert's perspective, this event underscores the increasing importance of sustainability in space activities, akin to environmental considerations in terrestrial transport. As satellite launches and operations proliferate, the principles of controlled reentry and the minimization of space debris become crucial not only for protecting space environments but also for ensuring safe access to space for future missions. The lessons learned from the Cluster mission and Salsa’s targeted reentry are vital in developing regulations and technologies that promote responsible space exploration, much like how transportation sectors strive for sustainable practices on Earth.