Targeting Method

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

Definition

The targeting method is a traditional orbit keeping strategy that minimizes a weighted combination of orbit deviation and control effort. At each control epoch, the method computes a corrective maneuver that drives the spacecraft back toward the reference orbit while minimizing fuel consumption.

Formulation

The targeting method solves an optimization problem at each control step:

\min_{\Delta v} \left( \| \delta \mathbf{x}(t_f) \|^2 + \rho \| \Delta v \|^2 \right)

where $\delta \mathbf{x}(t_f)$ is the orbit deviation at the target time, $\Delta v$ is the control velocity increment, and $\rho$ is a weighting parameter that balances orbit accuracy against fuel consumption.

Process

Determine current orbit state through navigation
Predict future orbit evolution without control
Compute the corrective maneuver that minimizes the cost function
Apply the maneuver at the designated control epoch
Repeat at the next control cycle

Characteristics

Feature	Description
Control type	Impulse thrust (discrete maneuvers)
Optimality	Minimizes weighted deviation-control trade-off
Robustness	Handles moderate orbit perturbations
Fuel efficiency	Generally efficient, but may not be globally optimal

References

Chen Yuju. DRO Orbit Design and Control Research for Cislunar Space Situation Awareness[D]. 2024.