Originally Posted by
ORAC
Oops. Was the storm predicted?
Space weather forecasting is still a very inexact art. The solar event was noted but there were no warnings issued about it’s effect on the upper atmosphere.
From Spaceweather.com:
Two days before launch a CME hit Earth's magnetic field. It was not a major space weather event. In fact, the weak impact did not at first spark any remarkable geomagnetic activity. However, as Earth passed through the CME's wake, some sputtering
G1-class geomagnetic storms developed. It was one of these minor storms that caught the Starlink satellites on Feb. 4th.
Geomagnetic storms heat Earth's upper atmosphere. Diaphanous tendrils of warming air literally reached up and grabbed the Starlink satellites. According to SpaceX, onboard GPS devices detected atmospheric drag increasing "up to 50 percent higher than during previous launches."
"The Starlink team commanded the satellites into a safe-mode where they would fly edge-on (like a sheet of paper) to minimize drag," says SpaceX. "Preliminary analysis show the increased drag at the low altitudes prevented the satellites from leaving safe-mode to begin orbit raising maneuvers, and up to 40 of the satellites will reenter or already have reentered the Earth’s atmosphere."