The European Space Agency has succeeded in bringing an end-of-life satellite back to Earth by controlling its trajectory! It was one of the four satellites making up the Cluster mission, which studied our magnetosphere, the protective shield of life on Earth, for 24 years.
Salsa has successfully returned to Earth, leaving behind the quartet it formed with the three other satellites of the European Space Agency’s (ESA) Cluster mission. On September 8, 2024, at 8:47 p.m. Paris time, the 1,200-kilogram satellite entered the atmosphere at high speed – initially at 28,000 km/h before the increasingly dense air layers slowed it down to around 800 km/h.
The first ever “targeted return”
Heating from intense friction melted and vaporized most of its material, and the remaining debris plunged as planned into the South Pacific Ocean. ESA has thus successfully achieved the first “targeted reentry” ever.
This deorbiting maneuver had been planned for a long time to avoid debris reaching populated areas. And in January 2024, Salsa had its orbit modified so that its reentry trajectory would reach this point in the ocean, far from any populated region. The behavior of the satellite was then monitored over the months and its trajectory has since undergone only one adjustment.
First recorded observation of a satellite re-entry, taken from an aircraft. Credit: ESA/ROSIE/University of Southern Queensland
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Magnetosphere and “killer electrons”
Today, space rules require that risks be minimized when a spacecraft returns to Earth. But this was not the case in the 1990s, when the Clusters were designed. As a result, Salsa’s uncontrolled reentry could have occurred anywhere on the globe, like an asteroid.
Salsa was one of four identical satellites in the Cluster mission – along with Samba, Rumba and Tango – launched in July 2000 to study the interaction between the solar wind and the Earth’s magnetosphere over nearly two solar cycles – each lasting an average of 12 years. The four satellites made it possible to carry out for the first time […]
- sciencesetavenir.fr
