Maneuvers and transfers¶

All the closed-form Δv tools live in the Maneuvers reference. Magnitudes are always positive.

Hohmann transfer LEO → GEO¶

{
  "currentCircularRadius": 6778000,
  "targetCircularRadius": 42164000,
  "centerOfMotion": "EARTH"
}

Tool: ComputeHohmannTransferDeltaV. Returns the two impulse magnitudes and the one-way transfer time.

Bi-elliptic alternative¶

For large radius ratios (r2 / r1 ≳ 11.94) a bi-elliptic transfer via an intermediate apogee can beat a Hohmann. Pick an intermediate radius greater than both endpoints:

{
  "currentCircularRadius": 6778000,
  "intermediateRadius": 200000000,
  "targetCircularRadius": 42164000,
  "centerOfMotion": "EARTH"
}

Tool: ComputeBiEllipticTransferDeltaV. Returns three impulse magnitudes and the total transfer time.

Pure inclination change¶

{ "velocity": 7500, "deltaInclinationRad": 0.087266 }

Tool: ComputeInclinationChangeDeltaV. Reminder: pure plane changes are expensive — at LEO speeds, a 5° change is already ~650 m/s.

Combined inclination + RAAN¶

{
  "velocity": 7500,
  "currentInclinationRad": 0.9006,
  "targetInclinationRad": 1.0996,
  "deltaRaanRad": 0.0
}

Tool: ComputeCombinedPlaneChangeDeltaV.

Apsidal changes¶

To raise apogee from a 200 km × 200 km LEO to a 200 km × 35786 km transfer:

{
  "perigeeRadius": 6578000,
  "currentApogeeRadius": 6578000,
  "targetApogeeRadius": 42164000,
  "centerOfMotion": "EARTH"
}

Tool: ComputeApogeeChangeDeltaV. The mirror tool ComputePerigeeChangeDeltaV raises/lowers perigee from apogee.

Phasing (circular rendezvous)¶

{
  "currentCircularRadius": 6778000,
  "centerOfMotion": "EARTH",
  "deltaTrueAnomalyRad": 0.1745,
  "revolutions": 3
}

Tool: ComputePhasingDeltaV. Returns the magnitude of the first impulse; the second equal-magnitude impulse re-circularizes, so the budget is 2 × returned value.

Lambert transfer¶

For two arbitrary state vectors with their epochs, use SolveLambert — see Lambert solver.

Apply an instantaneous Δv¶

ApplyImpulsiveDeltaV takes a state vector and a Δv vector (same frame), and returns the post-burn state. Position, epoch, frame and center of motion are preserved.

Numerical propagation through a maneuver chain¶

For an end-to-end mission simulation that integrates a maneuver chain into the trajectory (perturbations, drag, SRP, geopotential, constraint windows), see Mission scenarios.