THE STARLINK INCIDENT IS NOT WHAT WE THOUGHT: It never made sense. On Feb. 3rd, 2022, SpaceX launched a batch of 49 Starlinks to low-Earth orbit–something they had done many times before. This time was different, though. Almost immediately, dozens of the new satellites began to fall out of the sky.
A more accurate statement might have read “…impacted by a very minor geomagnetic storm.” The satellites flew into a storm that barely registered on NOAA scales: It was a G1, the weakest possible, unlikely to cause a mass decay of satellites. Something about “The Starlink Incident” was not adding up.
Space scientists Scott McIntosh and Robert Leamon of Lynker Space, Inc., have a new and different idea: “The Terminator did it,” says McIntosh.
Not to be confused with the killer robot, McIntosh’s Terminator is an event on the sun that helps explain the mysterious progression of solar cycles. Four centuries after Galileo discovered sunspots, researchers still cannot accurately predict the timing and strength of the sun’s 11-year solar cycle. Even “11 years” isn’t real; observed cycles vary from less than 9 years to more than 14 years long.
Above: Oppositely charged bands of magnetism march toward the sun’s equator where they “terminate” one another, kickstarting the next solar cycle. [more]
McIntosh and Leamon realized that forecasters had been overlooking something. There is a moment that happens every 11 years or so when opposing magnetic fields from the sun’s previous and upcoming solar cycles collide. They called this moment, which signals the death of the old cycle, “The Termination Event.”
After a Termination Event, the sun roars to life–”like a hot stove where someone suddenly turns the burner on,” McIntosh likes to say. Solar ultraviolet radiation abruptly jumps to a higher level, heating the upper atmosphere and dramatically increasing aerodynamic drag on satellites.
This plot supports what McIntosh and Leamon are saying:
The histogram shows the number of objects falling out of Earth orbit each year since 1975. Vertical dashed lines mark Termination Events. There’s an uptick in satellite decay around the time of every Terminator, none bigger than 2022.
As SpaceX was assembling the doomed Starlinks of Group 4-7 in early 2022, they had no idea that the Terminator Event had, in fact, just happened. Unwittingly, they launched the satellites into a radically altered near-space environment. “Some of our satellite partners said it was just pea soup up there,” says Leamon.
SpaceX wasn’t the only company hit hard. Capella Space also struggled in 2022 to keep its constellation of Synthetic Aperture Radar (SAR) satellites in orbit.
“The atmospheric density in low Earth orbit was 2 to 3 times more than expected,” wrote Capella Space’s Scott Shambaugh in a paper entitled Doing Battle With the Sun. “This increase in drag threatened to prematurely de-orbit some of our spacecraft.” Indeed, many did deorbit earlier than their 3-year design lifetimes.
The Terminator did it? It makes more sense than a tiny storm.