Configuration optimization design method for spacecraft with stabilized drag-augmentation spheres

The rapid increase in the number of low Earth orbit (LEO) spacecraft, combined with the extremely slow natural deorbiting time, has made the already limited orbital resources even more scarce, posing a serious threat to normal space activities in the region. To ensure the safety and sustainable development of the space environment, it is recommended that spacecraft be equipped with deorbit devices, such as drag spheres, to reduce their altitude at the end of their operational life, allowing them to burn up in the atmosphere. The drag sphere device inflates into a spherical shape using gas canisters, thereby increasing the spacecraft’s windward surface area, which in turn amplifies the atmospheric drag effect and facilitates rapid deorbiting. This paper proposes an optimized design method for a drag sphere configuration with stable guidance. For any deorbiting mission where the orbital parameters, mass, and other specifications of the target spacecraft are known, this method ensures the optimization of both the shape and attitude stability of the drag-enhanced spacecraft. It also satisfies the time constraints for deorbiting, thus ensuring the safety and reliability of the process. The configuration parameters of the drag sphere include radius, number of segments, and installation offset. This research lays the foundation for the configuration design and engineering application of drag spheres.