After 24 years of research, the Salsa satellite (Cluster 2) burned up in a controlled entry into the atmosphere, (thereby) marking the end of the mission and strengthening our understanding of the magnetosphere and space
The Cluster mission culminated with the satellite's planned reentry into the atmosphere, contributing to the understanding of Earth's magnetosphere and setting new standards in sustainable space practices. (Illustration). Credit: ESA – European Space Agency.
The European Space Agency's satellite, "Salsa" from the Cluster Group, has completed its historic mission with a targeted entry into the Earth's atmosphere, a move that contributed to the reduction of space debris and deepened the understanding of space weather.
This entry marks the end of a 24-year mission that has revealed crucial insights into Earth's magnetosphere and how it interacts with the solar wind. This opened the way for future missions to improve global communication and security in space and aviation.
The satellite, known as Salsa (Cluster 2), entered Earth's atmosphere on September 8, 2024 at 20:47 Central European Time (CEST), over the South Pacific Ocean. This area was chosen to minimize the risk of parts of the satellite hitting the ground.
During the last two decades that Cluster 2 has been in space, it has provided invaluable data on the interaction between the Sun and Earth's magnetic field, helping us better understand and predict space weather. With the first intentional entry of its kind, Cluster will also be remembered in history thanks to another reason - the transformation of the European Space Agency into a world leader in the field of sustainable space exploration.
The re-entry took place after Salsa's orbit was adjusted in January 2024, with the aim of targeting an area as far as possible from populated areas, thus ensuring that if there is a part of the satellite that survives the entry into the atmosphere - it will fall into the open ocean.
Over the past few days, weeks and months, operators of the European Space Agency's satellite closely followed Salsa as it approached Earth, making just one slight adjustment in the satellite's orbit to keep it on track.
The European Space Agency's "zero waste" policy
Nowadays, satellite missions are designed according to regulations that require reducing the risk of damage when returning to Earth. However, when Cluster was built in the 90s, these regulations did not yet exist. Without intervention, the cluster's four satellites would have entered Earth's atmosphere naturally—but with less control over the exact time and location of the event.
The European Space Agency's Director of Operations, Rolf Densing, explains why the agency chose to end the mission this way: "Salsa's re-entry has always been very low risk, but we wanted to push the boundaries and reduce the risk even further, demonstrating our commitment to a 'zero waste' policy ' of the European Space Agency."
"By studying how and when Salsa and the other three satellites of the cluster burn up in the atmosphere, we are learning a lot about the science of re-entry, hopefully we can apply this approach to other satellites when they reach the end of their lives."
Discovering the invisible shield of the earth
image captionSalsa's re-entry marks the end of a unique mission, which will ultimately help protect humanity from our stormy sun.
water? heat? minerals? All of these are essential to life, but are not unique to Earth. Perhaps the only thing that makes Earth a unique world where life can thrive is its strong magnetosphere.
Just a few hundred kilometers above our heads, an ongoing battle is going on between the forces of nature. Like a ship in a never-ending storm, Earth is bombarded by swarms of particles ejected from the Sun at supersonic speeds.
The magnetic field and electric currents that surround the earth create complex forces that have a tremendous impact on everyday life. You can think of the field as a kind of giant bubble that protects us from cosmic radiation and charged particles coming from the sun. Credit: ESA/ATG medialab.
Most of the particles from the solar wind are deflected by the magnetosphere, and pass by the Earth without causing damage. But Earth's shield is not completely immune. Solar wind bursts can squeeze it hard, inject energetic particles through weak points, and damage electronic equipment including vital satellites in space.
Exploring the secrets of the magnetosphere
It may sound like science fiction, but scientists have been studying the ongoing battle between the Sun and Earth for many years, first from the ground and then with the help of individual satellites. But the complexity of the connection between the sun and the earth has always eluded them. Until the cluster task arrived.
badges: cluster, Salsa satellite, European Space Agency, magnetosphere, space debris, reentry, magnetic field, sustainable space, solar winds, sustainability, space weather, space exploration, mission termination, satellite
