[freebeard]

Via Hacker News:

www.space.com: Wild solar weather is causing satellites to plummet from orbit. It's only going to get worse.
By Tereza Pultarova published about 9 hours ago
The change coincided with the onset of the new solar cycle, and experts think it might be the beginning of some difficult years.r

"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."

"There is a lot of complex physics that we still don't fully understand going on in the upper layers of the atmosphere where it interacts with the solar wind," Stromme said. "We know that this interaction causes an upwelling of the atmosphere. That means that the denser air shifts upwards to higher altitudes."

All spacecraft around the 250-mile altitude are bound to have problems, Stromme said. That includes the International Space Station, which will have to perform more frequent reboost maneuvers to keep afloat, but also the hundreds of cubesats and small satellites that have populated low Earth orbit in the past decade. Those satellites — a product of the new space movement spearheaded by private entrepreneurs pioneering simple, cheap technologies — are particularly vulnerable.
...
"Many of these [new satellites] don't have propulsion systems," Stromme said. "They don't have ways to get up. That basically means that they will have a shorter lifetime in orbit. They will reenter sooner than they would during the solar minimum."
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By coincidence (or beginner's luck), the onset of the new space revolution came during that sleepy solar cycle. These new operators are now facing their first solar maximum. But not only that. The sun's activity in the past year turned out to be much more intense than solar weather forecasters predicted, with more sunspots, more coronal mass ejections and more solar wind hitting our planet.

"The solar activity is a lot higher than the official forecast suggested," Hugh Lewis, a professor of engineering and physical sciences at the University of Southampton in the U.K. who studies the behavior of satellites in low Earth orbit, told Space.com. "In fact, the current activity is already quite close to the peak level that was forecasted for this solar cycle, and we are still two to three years away from the solar maximum."

It turns out the Starlink constellation orbits higher than the International Space Station. I did not know that.