Nonspherical Perturbation

Author: Tianjiang Shuo Website: https://cislunarspace.cn

Definition

The difference between a celestial body's actual gravitational field and that of an ideal point mass. The gravitational fields of the Earth and Moon are modeled via spherical harmonic expansion; higher expansion orders yield greater accuracy but increase computational cost. In cislunar guidance, near-Earth segments use high-order expansion (e.g., order 21), while distant segments can be reduced to low-order or point-mass models.

Application Value

This concept is of significant importance in cislunar space research and technical applications, helping to deepen understanding of related physical mechanisms and engineering implementations.

References

• Wang 等 - 2024 - Low-energy earth–moon transfer autonomous guidance considering high-fidelity orbital dynamics