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Delta-V Calculator (Tsiolkovsky)

Rocket-equation solver for orbital maneuvers. Δv = Isp · g₀ · ln(m_wet / m_dry). Forward mode (given masses → Δv) and reverse mode (given Δv → propellant needed).

Inputs

Propulsion

Typical: 220-300s (monoprop), 300-340s (biprop), 1500-4500s (electric), 430s (LH2/LOX).

Masses

Maneuver presets

Result

Wet mass250.00 kg
Mass ratio (m_wet / m_dry)1.250
Exhaust velocity (Isp · g₀)3040.1 m/s
Δv available678.4 m/s

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Frequently asked questions

What is Tsiolkovsky's rocket equation?

Δv = v_e · ln(m_wet / m_dry), where v_e = Isp · g₀ is the exhaust velocity. It tells you how much velocity change a vehicle can produce given its initial and final mass, assuming a constant exhaust velocity (impulsive approximation).

Why does high Isp matter?

Propellant is exponential in Δv. Doubling Isp halves the mass ratio needed for a given Δv. That's why electric propulsion (Isp 1,500-4,500s) is transformative for deep-space and GEO missions despite low thrust.

What does this tool NOT account for?

Finite-burn gravity losses, atmospheric drag, steering losses, multi-stage vehicles, or variable thrust profiles. For real maneuver planning use the Finite Burn and Porkchop tools in the Aerospace Pack.

Upgrade for real maneuver planning

  • Finite-burn gravity loss modeling
  • Multi-burn maneuver sequencing with launch windows
  • Hohmann, bi-elliptic, Lambert, and low-thrust solvers
  • Porkchop plots for interplanetary transfers
  • Export maneuver schedule to ops timeline
See the full Aerospace Pack →