Pure Plane Change Impulse
Calculate an instantaneous pure plane rotation at constant speed; actual node availability is not inferred.
Description
Rotating an orbital velocity vector without changing its speed requires an impulse.
Rotating an orbital velocity vector without changing its speed requires an impulse. The cost grows with plane angle and speed, motivating plane changes at an appropriately located low-speed point.1
Calculate an instantaneous pure plane rotation at constant speed; actual node availability is not inferred.
When to use Pure Plane Change Impulse
Use this tool to calculate an instantaneous pure plane rotation at constant speed; actual node availability is not inferred.
Prepare the orbital state or model parameters in one reference frame. Confirm compatible distance/time units and the stated angular and gravitational-parameter conventions.
How to use Pure Plane Change Impulse and understand its results
- Prepare the orbital state or model parameters in one reference frame. Confirm compatible distance/time units and the stated angular and gravitational-parameter conventions.
- Enter orbitalSpeed, inclinationChangeDegrees using the field table and calculation rules, then run the tool.
- Read planeChangeDeltaV. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| orbitalSpeed | Orbital speed | number | Required |
| inclinationChangeDegrees | Inclination change degrees | number | Required |
Enter a nonnegative speed and a plane rotation from 0 through 180 degrees. The tool converts the half-angle to radians and returns the velocity-change magnitude in the speed's unit. Zero angle or speed gives zero; 180 degrees reverses the vector.
deltaV = 2 × speed × sin(angle/2) Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| planeChangeDeltaV | Plane change delta v | number |
{
"input": {
"orbitalSpeed": 2,
"inclinationChangeDegrees": 60
},
"output": {
"planeChangeDeltaV": 1.9999999999999998
}
}Limitations and assumptions
It does not find a usable node or account for a simultaneous speed change, finite burn or trajectory constraints. The two equal-speed vectors are assumed co-located.
Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Combined Plane Change Savings: Compare a combined speed/plane-change impulse with speed change plus a plane change at the lower endpoint speed; geometry must be co-located. For a complementary task, use Powered Flyby Velocity Budget: Budget a local powered-flyby velocity vector change and specific kinetic-energy change from supplied periapsis speeds and angle; no B-plane trajectory is solved.
References
-
Pure Plane Change Impulse — tool.io
Similar or alternative tools
- Combined Plane Change Savings
Compare a combined speed/plane-change impulse with speed change plus a plane change at the lower endpoint speed; geometry must be co-located.
- Powered Flyby Velocity Budget
Budget a local powered-flyby velocity vector change and specific kinetic-energy change from supplied periapsis speeds and angle; no B-plane trajectory is solved.