[Space] 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."
Satellites orbiting close to Earth always face the drag of the residual atmosphere, which gradually slows the spacecraft and eventually makes them fall back to the planet. (They usually don't survive this so-called re-entry and burn up in the atmosphere.) This atmospheric drag forces the International Space Station's controllers to perform regular "reboost" maneuvers to maintain the station's orbit of 250 miles (400 km) above Earth.
This drag also helps clean up the near-Earth environment from space junk. Scientists know that the intensity of this drag depends on solar activity — the amount of solar wind spewed by the sun, which varies depending on the 11-year solar cycle. The last cycle, which officially ended in December 2019, was rather sleepy, with a below-average number of monthly sunspots and a prolonged minimum of barely any activity. But since last fall, the star has been waking up, spewing more and more solar wind and generating sunspots, solar flares and coronal mass ejections at a growing rate. And the Earth's upper atmosphere has felt the effects.
The Swarm constellation, launched in 2013, consists of three satellites, two of which orbit Earth at an altitude of 270 miles (430 km), about 20 miles (30 km) above the International Space Station. The third Swarm satellite circles the planet somewhat higher — about 320 miles (515 km) above ground. The two lower-orbiting spacecraft were hit more by the sun's acting out than the higher satellite was, Stromme said.
The situation with the lower two got so precarious that by May, operators had to start raising the satellites' altitude using onboard propulsion to save them.
ESA's Swarm satellites are not the only spacecraft struggling with worsening space weather. In February, SpaceX lost 40 brand-new Starlink satellites that were hit by a solar storm just after launch.
More solar radiation usually means more extreme weather on Earth as the energy from it powers things. 10-1 the greens shreek of global warming until the end of time