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Orbital Period Fuel Requirements Estimator

The Orbital Period Fuel Requirements Estimator approximates propellant needed for recurring small corrections tied to orbital revolutions. You provide the orbital period, mission duration, maneuver interval in orbits, delta-v per correction, spacecraft initial mass, and propulsion specific impulse. The calculator then estimates maneuver count, cumulative delta-v, final mass, and propellant consumed.

This model is useful for first-pass station-keeping or maintenance budgeting when a correction cadence can be expressed as one maneuver every fixed number of orbits. It uses the ideal Tsiolkovsky rocket equation and assumes all entered correction delta-v accumulates in the same propulsion budget. It does not predict how much station keeping a real orbit will require; that depends on perturbations, attitude strategy, mission geometry, and control policy.

Mission inputs

min
days
orbits
m/s
kg
s
Result
—
Calculated result
Estimated corrections—
Total delta-v—
Final mass—
Propellant required—

1. Enter orbital cadence
Set the period so mission duration can be converted into total revolutions.

2. Set how often corrections occur
Enter the number of orbits between planned maintenance maneuvers.

3. Enter delta-v per correction
Use the expected velocity change allocated to each correction, in meters per second.

4. Provide spacecraft and propulsion values
Initial mass and specific impulse determine how cumulative delta-v translates into propellant.

5. Review maneuver count and fuel
The tool counts completed correction intervals and applies the summed delta-v to the ideal rocket equation.

The model first determines how many complete correction intervals occur, then applies their total delta-v to the ideal rocket equation:

Mission orbits = mission minutes / orbital period Corrections = floor(mission orbits / interval orbits) Δv_total = corrections × Δv_per correction m_final = m_initial / exp(Δv_total / (Isp × g₀)) Propellant = m_initial − m_final

Isp is specific impulse in seconds and g₀ = 9.80665 m/s². Delta-v is in m/s and mass in kilograms. The equation assumes a single effective propulsion performance, instantaneous ideal burns, and no reserve. The correction cadence and delta-v are user assumptions, not predictions of environmental disturbance.

What the result means

The main result is ideal propellant consumed by the counted recurring corrections over the mission span.

Add mission-specific reserves, disposal maneuvers, attitude-control usage, mixture constraints, and non-ideal performance separately.

Given

  • Orbital period: 96 min
  • Mission: 365 days
  • Correction every 50 orbits
  • 0.2 m/s per correction
  • Initial mass: 500 kg
  • Isp: 220 s

Calculation
Mission orbits = 365 × 1,440 / 96 = 5,475. Corrections = floor(5,475 / 50) = 109. Total Δv = 21.8 m/s. Final mass = 500 / exp(21.8 / (220 × 9.80665)) ≈ 494.97 kg.

Result
Ideal propellant ≈ 5.03 kg.

This covers only the recurring corrections represented by the entered cadence and delta-v.

Does the calculator predict station-keeping delta-v?

No. You supply delta-v per correction and the interval. Those inputs should come from mission analysis, heritage data, or a higher-fidelity perturbation model.

Why does maneuver count round down?

A correction is counted only after a complete interval of orbits has elapsed. This avoids charging propellant for a maneuver scheduled beyond the entered mission duration.

Can I use electric propulsion specific impulse?

Yes, if the delta-v budget and propulsion mode are compatible with the assumed maneuver cadence. Low-thrust operations may require a more detailed finite-burn model.

Where should propellant reserve be included?

This page reports ideal consumption only. Apply a separate reserve or contingency policy to the result rather than hiding it inside specific impulse.

How is this different from a rocket delta-v fuel estimator?

This calculator derives total delta-v from recurring orbit-based corrections. A general delta-v fuel estimator typically starts from a mission delta-v requirement directly.