Orbit Keeping
Author: Tianjiang Says
Website: https://cislunarspace.cn
Definition
Orbit keeping (station-keeping) refers to the set of control strategies and maneuvers used to maintain a spacecraft on or near its designed reference orbit, counteracting perturbations from environmental forces, navigation errors, and execution uncertainties.
Classification by Control Mode
| Mode | Description | Characteristics |
|---|---|---|
| Impulse thrust | Discrete maneuvers at specific epochs | Closed-loop, lower fuel, coupled with orbit determination |
| Continuous thrust | Persistent low-thrust propulsion | Open-loop, higher fuel, decoupled from orbit determination |
Classification by Strategy
| Strategy | Description |
|---|---|
| Targeting method | Minimize weighted deviation-control cost at each epoch |
| Dynamic target method | DE-optimized control parameters for lower fuel consumption |
| Floquet mode method | Eliminate unstable perturbation components |
Orbit Keeping for DRO
DRO orbit keeping has unique characteristics:
- Inherent stability: DROs are naturally stable, requiring only small corrections
- Perturbation sources: Solar radiation pressure, solar gravity, navigation and execution errors
- Fuel consumption: DRO station-keeping typically requires very low ΔV per year
- Control frequency: Can be relatively infrequent due to orbit stability
Error Sources
The main error sources affecting orbit keeping performance:
- Insertion errors: Initial orbit deviation from the designed reference
- Navigation errors: Uncertainty in orbit determination
- Actuator errors: Imperfect execution of control maneuvers
- Environmental perturbations: Unmodeled forces (solar radiation pressure, third-body gravity)
Related Concepts
- Targeting Method
- Dynamic Target Method
- Floquet Mode Method
- Impulse Thrust
- Distant Retrograde Orbit (DRO)
References
- Chen Yuju. DRO Orbit Design and Control Research for Cislunar Space Situation Awareness[D]. 2024.