A new approach to modelling space weather impact on the aerodynamic drag of LEO objects

The ability of space-based infrastructure to provide essential and sustained benefits to humanity in critical areas such as communications, Earth observation, technology development, navigation, and space exploration is increasingly threatened by the growing amount of orbital debris. A deliberate, urgent, and sustained effort must be made to resolve the problem of space debris and to ensure a risk-free utilisation and sustainability of the space environment. In this paper, we review the concept and appropriate technologies for orbital sustainability in low Earth orbit (LEO) and provide model-based space situational awareness (SSA) for LEO debris. We simulate the long-term evolution of the orbital decay of eight catalogued LEO objects due to space weather-enhanced atmospheric drag, as a function of solar-geophysical indices during Jan-Jun 2024, using the ephemeris data-assisted calibration (EDAC) method. The simulated mean heights and orbit decay rates of the objects compared well with their historical orbital data, although slight deviations were observed depending on the objects’ altitudes. The objects between 500 and 600 km altitude experienced an 8-fold drag effect compared to objects between 600 and 700 km altitude. We also investigated the short-term enhancement of aerodynamic drag during the severe geomagnetic storm of 10–11 May 2024 and found that the storm increased the objects’ orbit decay rates by 233–266% during its main phase, with up to 7-fold relative impact for a group separation of about 60 km. The impact levels were strongly influenced by storm-driven thermospheric density enhancements at the object altitudes, in combination with object-specific orbital dynamics, ballistic properties, and operational characteristics. We also showed that the long-term evolution of atmospheric drag-induced orbital decay on the objects obtained from both EDAC simulated results and the objects’ historical data were also consistent with the signature of solar cycle variation. The results demonstrate significant improvement in drag modeling and that the simulation of a long-term drag impact for maintaining reliable SSA for LEO objects is achievable.