In late 2021, operators of the European Space Agency’s (ESA) Swarm constellation noticed something worrying: The satellites, which measure the magnetic field around Earth, started sinking toward the atmosphere at an unusually fast rate — up to 10 times faster than before. The change coincided with the onset of the new solar cycle, and experts think it might be the beginning of some difficult years for spacecraft orbiting our planet.
“In the last five, six years, the satellites were sinking about two and a half kilometers [1.5 miles] a year,” Anja Stromme, ESA’s Swarm mission manager, told Space.com. “But since December last year, they have been virtually diving. The sink rate between December and April has been 20 kilometers [12 miles] per year.”