SpaceX lost 38 Starlink Satellites due to a CME

I wrote last year about the effect of CME on the thermospheric density and what are the effects on satellites inside the thermosphere, typically at the altitude of the Starlink satellites. You can find this post here.

Solar cycle 25 is well underway now, and from the look of it, it looks like the sun is in a strong unrest. It might be a very active solar cycle, that some predictions made put it at the same level than the cycle 20, which peaked in the 70’s. Little known fact about the 20th solar cycle: one of the strongest storm from that cycle happened the 4th August 1972 and was the fastest to travel the distance Sun-Earth in just 14.6h. It usually takes between 20h and a few days for a CME to travel that distance [1–2].

Strong solar cycle mean strong CME’s that have an impact on satellites, and this is what SpaceX had to deal with in early this year. They launched a rocket the 2nd February carrying 49 Starlink satellites [3]. SpaceX lost 38 of those satellites [4] almost immediately because of the increased drag caused by the impact of the CME on the thermosphere. The uncontrolled reentry of the satellites can be seen in video, taken from Puerto Rico.

This kind of event really shows how sensitive our equipment up there is to the tantrum of the sun. These satellites were especially sensitive because of their low orbit after launch.