Today, ‘Impossible Satellite’ Expected to Descend to Earth

Today, a European Space Agency satellite is set to plunge back to Earth. While the Aeolus satellite was not built for a controlled reentry, scientists are making efforts to guide its descent into the Atlantic Ocean. Flight controllers have been using the satellite’s remaining fuel to activate its thrusters and gradually lower it from 200 miles to 75 miles above the Earth’s surface. “At that point, the atmospheric drag should pull it down,” explains Isabel Rojo, ESA’s spacecraft operations manager, in an interview with the BBC. “We anticipate it will reenter the Earth’s atmosphere over the Atlantic Ocean, moving from south to north.” This endeavor marks a pioneering attempt in satellite reentry.

Approximately 20% of the 3,000-pound satellite is predicted to survive the reentry. The space agency’s objective is to minimize any risks to people and property and establish best practices for future reentries. Holger Krag, head of ESA’s space safety program, remarks, “The spacecraft is not designed for a fully controlled reentry, such as targeting a predetermined small area,” as reported by The Guardian. “Only rocket stages, spaceships, or cargo ships have accomplished this thus far, not satellites.”

The final commands were transmitted to Aeolus last Friday, according to the ESA’s live reentry blog. Earlier, during a “challenging” stage of the atmosphere, the team had to make quick decisions when the words “major anomaly” were heard over the communication loop. This weather satellite, which has now gone defunct, was launched in 2018 and was the first to utilize an ultraviolet laser for mapping global wind patterns. The BBC reports that plans for replacements are underway, although Aeolus’ initial development was so intricate that it was dubbed the “impossible satellite.” (Read more satellite stories.)