Size average orbital energy, eclipse battery demand, and minimum solar-array output from period and operating loads. Separate sunlight and eclipse durations reveal whether the energy balance closes.
Battery energy equals eclipse load × eclipse hours × (1 + margin).
Minimum array output covers the sunlight load and replenishes eclipse energy during the available illuminated portion of each orbit.
Array degradation, pointing, thermal limits, battery depth of discharge, and peak loads require additional sizing factors.
For a 95-minute orbit with 35 minutes of eclipse, 420 W sunlight load, 360 W eclipse load, 85% efficiency, and 20% margin, the minimum array output is about 800.47 W.
Enter distance from the body's center. Add the body's mean radius to altitude before using the calculator.
Yes. It uses a two-body circular-orbit approximation unless the page explicitly asks for a mission allowance.
Yes. Replace the gravitational parameter and radius inputs with values for the selected body.
High-fidelity tools may include oblateness, atmospheric drag, third-body gravity, eccentricity, and numerical propagation.
No. They are preliminary engineering estimates and should be checked with validated mission-analysis software.
| Output | Use |
|---|---|
| Energy per orbit | Average cycle demand |
| Battery energy | Stored energy needed for eclipse |
| Minimum array output | Sunlight generation target |
| Power margin | Allowance on spacecraft loads |