🛰️ Low Orbit Eclipse, Beta Angle and Battery Depth of Discharge (2D)

Diagram of a circular low orbit around the Earth with the Sun on one side, showing the part of every orbit the satellite spends in the Earth shadow and the battery that must carry the load through it. Set the altitude, the beta angle between the Sun and the orbit plane, the station load, the solar array output, the battery capacity and the charging efficiency, and see the orbit period, the eclipse time, the battery depth of discharge and the array needed to break even. The eclipse fraction, the orbit period, the full-sun beta angle and the energy bookkeeping are checked numerically, with four in-page numerical checks.

2D · HTML5 Canvas 2D · 60 FPS target · runs fully client-side, no install