Starting January 29, 2022, a series of eruptions began rocking the surface of the sun. Scientists and forecasters watching from NOAA’s Space Weather Prediction Center (SWPC) issued alerts that the events would likely trigger prolonged but minor geomagnetic storming; such minor storms rarely impact lives and infrastructure. 

Meanwhile, in Cape Canaveral, FL, SpaceX Starlink was preparing to launch a new batch of satellites into low-Earth orbit a few days later. After the successful launch, however 38 of the 49 Starlink’s satellites failed, deorbiting and burning up during reentry into Earth’s atmosphere. 

Now, a collaboration among NOAA and CIRES/CU Boulder scientists and Starlink experts confirms the cause for the loss—high satellite drag conditions and reduced satellite stability due to the “minor” geomagnetic storm. The study, published in AGU's journal Space Weather, suggests that improved observations and forecasts for minor space weather events can help the commercial satellite industry avoid future satellite loss. Teams at NOAA and SpaceX are responding quickly, through model and forecast changes that better characterize low- and very-low Earth orbit environments, and satellite system updates.

Eruptions from the sun’s surface are common, with many traveling harmlessly into space. But when an eruption does travel towards Earth, it can create disturbances in Earth’s magnetic field, or geomagnetic storms. These storms produce the awe-inspiring northern lights, but can also result in significant disruptions to critical infrastructure, such as disrupting GPS signals and radio communications and damaging the electrical grid.

“This study demonstrates the benefits that can come from collaborative work between government and industry,” said Tzu-Wei Fang, Ph.D., lead author of the study and space scientist at SWPC.

To investigate the cause of the event, the research team, which included scientists from SWPC and CIRES and SpaceX Starlink’s Guidance Navigation Control team, used observations from the Starlink satellites and forecasts and numerical simulations from NOAA. 

The study confirms SpaceX’s preliminary analysis: the February geomagnetic storm created a disturbance in the upper atmosphere that enhanced satellite drag conditions and reduced satellite stability, leading to the loss of 38 satellites. The authors demonstrate that SWPC’s physics-based numerical model, called WAM-IPE, developed in part by CIRES scientists, captured the environment responsible for the Starlink satellite loss event, out-performing the empirical model used by the Starlink team for their analyses before their launch.

To read more about how NOAA and Starlink are responding to the incident, with enhanced services to satellite operators, for example, please read more from the National Weather Service.