Description
The Rendezvous Maneuver Software is a Software component responsible for performing rendezvous maneuvers to match the orbit of a chaser spacecraft with a target space object. It performs an approach sequence to align the orbits by outputting thruster fire requests and attitude reference commands.
Example Use Cases
- Cargo Resupply Missions: Compute approach maneuvers for cargo vehicles rendezvousing with a space station.
- Satellite Servicing: Plan approach trajectories for on-orbit inspection or repair missions.
- Formation Flying: Calculate maneuvers to establish relative positioning between spacecraft.
Module Implementation
The Rendezvous Maneuver Software processes navigation state data from both the chaser and target spacecraft to generate delta-velocity commands through a multi-stage maneuver sequence.
Maneuver Stages
The software executes a sequence of maneuvers to match the target orbit:
- Plane Change: Aligns inclination and right ascension of the ascending node (RAAN) with the target
- Hohmann Transfer: Matches semi-major axis and eccentricity with the target
- Phase Change: Adjusts true anomaly to synchronize position with the target
Alignment Checking
The software provides methods to check alignment status:
| Method | Description |
|---|---|
| IsPlaneAligned | Returns whether the chaser is aligned with the target’s orbital plane (inclination and RAAN) |
| IsRadiusAligned | Returns whether the chaser is aligned with the target’s radius (SMA and eccentricity) |
| IsPhaseAligned | Returns whether the chaser is aligned with the target’s phase (true anomaly) |
Key Properties
| Property | Description |
|---|---|
| CurrentManeuver | The current maneuver state of the RPO software |
| ThrustDirection_N | The current thrust direction for the thruster burn |
| ThrustFactor | A factor to scale the thrust force |
| MatchingInclinationDelta | Minimum inclination delta for plane change matching |
| MatchingAscensionDelta | Minimum RAAN delta for plane change matching |
| MatchingRadiusDelta | Radius delta for Hohmann stage matching |
| MatchingPeriodDelta | Time interval for matching periods at end of phase change |
| NearPlaneNode | Angle near the nodal line for firing thrusters during plane change |