Tsiolkovsky rocket equation API

Solves the Tsiolkovsky rocket equation either way: delta-v from a mass ratio, or propellant mass needed for a target delta-v, accepting exhaust velocity or specific impulse (Isp). Answers 'Delta-v for this mass ratio?', 'How much propellant for 9 km/s?'.

Price$0.06per request

MethodPOST

Route/v1/space/rocket-equation

StatusLive

MIME typeapplication/json

Rate limit120/minute

Cache0s public

spaceastronomytsiolkovskyrocket-equationdelta-vspecific-impulsepropellantastrodynamics

API URLhttps://x402.hexl.dev/v1/space/rocket-equation

Integration docs

Example request

{
  "specificImpulseS": 311,
  "initialMassKg": 549054,
  "finalMassKg": 25600
}

Example response

{
  "mode": "deltaV",
  "exhaustVelocityMs": 3049.8681,
  "specificImpulseS": 311,
  "initialMassKg": 549054,
  "finalMassKg": 25600,
  "massRatio": 21.447422,
  "propellantMassKg": 523454,
  "deltaVMs": 9349.6894,
  "deltaVKms": 9.349689,
  "interpretation": "Mass ratio 21.45 at Isp 311 s yields 9349.7 m/s of delta-v."
}

Input schema

{
  "type": "object",
  "properties": {
    "exhaustVelocityMs": {
      "type": "number"
    },
    "specificImpulseS": {
      "type": "number",
      "examples": [
        311
      ]
    },
    "initialMassKg": {
      "type": "number",
      "examples": [
        549054
      ]
    },
    "finalMassKg": {
      "type": "number",
      "examples": [
        25600
      ]
    },
    "deltaVMs": {
      "type": "number"
    }
  }
}

Output schema

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