Insights from the Gannon Geomagnetic Storm on Sustainable Satellite Operations

The Gannon geomagnetic storm of May 10-12, 2024 was Earth’s largest in over 20 years. During that intervening time, the nature of spacecraft operations changed considerably as decreasing launch costs and commercialization led to the the advent of proliferated satellite constellations in low Earth orbit (LEO). With the considerable increase in the population of satellites and debris in orbit, satellite conjunction assessment and collision avoidance has become necessary and common in operations to maintain safe mission execution. The Gannon storm stressed vulnerabilities in the existing infrastructure for space domain awareness and conjunction assessment. The robustness of this infrastructure is of critical importance to the long-term sustainability of the operating environment in low Earth orbit.

Geomagnetic storms have a multifaceted impact on satellite systems. The rapid expansion of the thermosphere causes unpredictable satellite drag. Conjunction screening requires accurate propagations of satellite trajectories several days in advance to plan and execute maneuvers. Drag uncertainty during storms has the potential to perturb satellite trajectories by tens of kilometers per day. The rapid drag decay from storms also necessitates orbit-raising for satellites in constellations to maintain nominal spacecraft separation for operations. Beyond satellite drag impacts, electronic components on space vehicles may be damaged or degraded from increased radiation exposure during storms. To protect against these effects, some operators opt to place their vehicles in a protected safe-mode if a storm is imminent. While this action mitigates the impacts of the radiation exposure, it also prevents those satellites from being able to perform collision avoidance maneuvers during that time. Finally, communication between ground terminals and satellites is sometimes interrupted during storms due to unpredictable ionospheric disturbances. This makes it difficult to receive data from satellites or command them during storm periods.

In this effort, we compile insights from satellite tracking data during the Gannon storm. Opportunities for increasing the robustness of conjunction assessment procedures are identified from observed issues during the storm period. Broader impacts on space sustainability and the satellite carrying capacity of LEO are also identified. This work highlights the role that variability in the space weather environment plays in short and long term operations in the near-Earth space environment.