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Satellite Link Fuel Requirements Estimator

The Satellite Link Fuel Requirements Estimator provides a first-order propellant estimate for station-keeping and orbit-maintenance delta-v over a mission. It converts annual delta-v and mission duration into a cumulative requirement, applies a contingency margin, and then uses the ideal rocket equation with spacecraft initial mass and specific impulse.

The communications link itself does not consume propellant; the connection is operational. Satellites need fuel to maintain the orbit and pointing environment that keeps the link serviceable. This calculator therefore frames propellant around link-supporting station keeping, relocation, momentum management, or other mission delta-v. It is best for early sizing before detailed maneuver schedules, depletion models, and disposal reserves are established.

Inputs

kg
m/s/yr
yr
%
s
Result
—
Estimated station-keeping propellant
Nominal lifetime delta-v—
Margin-adjusted delta-v—
Estimated final mass—

1. Enter spacecraft mass
Use mass at the start of the modeled station-keeping period.

2. Enter annual delta-v
Use the average station-keeping and orbit-maintenance requirement in meters per second per year.

3. Set mission duration
Enter the years covered by the estimate.

4. Apply delta-v contingency
Use a percentage margin for uncertainty or unplanned corrections.

5. Enter specific impulse
Use the propulsion-system Isp in seconds.

6. Review propellant
Treat the result as an idealized station-keeping fuel estimate, then add mission-specific residual or disposal requirements separately if needed.

Nominal lifetime Δv = Annual Δv × Mission years Adjusted Δv = Nominal Δv × (1 + Contingency/100) Final mass = Initial mass / exp(Adjusted Δv / (Isp × g₀)) Propellant = Initial mass − Final mass

The model uses g₀ = 9.80665 m/s² and assumes constant specific impulse with no staging or other mass changes.

What the result means

The main result estimates ideal propellant consumed to deliver the margin-adjusted lifetime station-keeping delta-v.

Add separate allocations for acquisition, relocation, collision avoidance, momentum unloading, graveyard or deorbit maneuvers when they are not already included in annual delta-v.

Given: 1,200 kg initial mass, 45 m/s/year, 7 years, 15% delta-v contingency, and 230 s Isp.

Calculation: Nominal Δv = 315 m/s. Adjusted Δv = 362.25 m/s. Mass ratio = exp(362.25/(230×9.80665)) ≈ 1.174. Final mass ≈ 1,022 kg, so propellant ≈ 178 kg.

Result: The ideal station-keeping estimate is about 178 kg of propellant.

Why is this called a Satellite Link fuel estimator?

It estimates propellant used to maintain the spacecraft geometry and operations that support the link; RF transmission itself does not burn propellant.

Should collision-avoidance maneuvers be included?

Include an allowance in annual delta-v or contingency if you want them represented. Detailed programs often budget them separately.

Does mass decrease during the calculation?

Yes. The rocket equation accounts for propellant depletion between initial and final mass over the cumulative delta-v.

Can I use electric propulsion Isp?

Yes, with an appropriate effective Isp, but long electric-propulsion burns can introduce operational and power constraints not represented here.

Does this include end-of-life disposal fuel?

Only if that delta-v is included in the annual requirement or contingency. Otherwise add the disposal maneuver separately in a dedicated budget.