x₀ Value
Author: Tianjiang Shuo
Website: https://cislunarspace.cn
Definition
A key parameter identifying a halo orbit, defined as the x-coordinate of the halo orbit at the positive z-plane crossing in the Earth-Moon synodic coordinate system. Each halo orbit in a family can be uniquely specified by its x₀ value, which maps to the orbit's z-axis amplitude.
Application Value
The x₀ value serves as an important reference orbit type in cislunar space orbit design, useful for target orbit selection and transfer scheme design. In practical missions, orbit design based on the x₀ value can satisfy specific mission constraints such as communication elevation angle, coverage area, and fuel optimality. Leveraging the characteristics of the x₀ value enables optimized transfer trajectory design for efficient Earth-Moon transfers. The x₀ value provides diverse orbit selection options for lunar exploration missions, facilitating flexible mission planning.
Related Concepts
References
- Parker and Born - 2008 - Direct lunar halo orbit transfers