Lagrange-point distances API

Returns L1/L2 distances from the secondary (Hill-sphere first-order r≈R·(mu/3)^(1/3)) and the L3 offset from the primary for a two-body system from the masses and separation. Answers 'How far is Sun-Earth L1/L2?', 'Where is the L2 halo region?'.

Price$0.06per request

MethodPOST

Route/v1/space/lagrange-points

StatusLive

MIME typeapplication/json

Rate limit120/minute

Cache0s public

spaceastronomylagrange-pointl1l2l3three-bodyhalo-orbitastrodynamics

API URLhttps://x402.hexl.dev/v1/space/lagrange-points

Integration docs

Example request

{
  "primaryMassKg": 1.98892e+30,
  "secondaryMassKg": 5.972168e+24,
  "separationM": 149597870700
}

Example response

{
  "primaryMassKg": 1.98892e+30,
  "secondaryMassKg": 5.972168e+24,
  "separationM": 149597870700,
  "massFraction": 0.000003003,
  "l1DistanceFromSecondaryM": 1496429035.102,
  "l1DistanceFromSecondaryKm": 1496429.0351,
  "l2DistanceFromSecondaryM": 1496429035.102,
  "l2DistanceFromSecondaryKm": 1496429.0351,
  "l3DistanceFromPrimaryM": 149598057866.262,
  "l3DistanceFromPrimaryKm": 149598057.8663,
  "note": "L1/L2 use the Hill-sphere first-order approximation r≈R·(μ/3)^(1/3); L4/L5 lead/trail the secondary by 60° at distance R.",
  "interpretation": "L1/L2 sit ~1496429 km from the secondary body."
}

Input schema

{
  "type": "object",
  "required": [
    "primaryMassKg",
    "secondaryMassKg",
    "separationM"
  ],
  "properties": {
    "primaryMassKg": {
      "type": "number",
      "examples": [
        1.98892e+30
      ]
    },
    "secondaryMassKg": {
      "type": "number",
      "examples": [
        5.972168e+24
      ]
    },
    "separationM": {
      "type": "number",
      "examples": [
        149597870700
      ]
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}