Spacecraft Thermal Balance in Orbit (2D)

Every orbiting spacecraft lives on a knife-edge between overheating in sunlight and freezing in the planet's shadow. This 2D top-down companion models the exact same energy balance as the 3D scene: a satellite orbits a planet while absorbing solar irradiance (scaled by its absorptivity and sunlit cross-section) and radiating heat away by the Stefan–Boltzmann law (scaled by its emissivity and surface area), with power cut to zero the moment it enters the shaded wedge behind the planet. Adjust orbital altitude to change the orbital period and eclipse duration, absorptivity and emissivity to model different thermal coatings, and thermal mass to see how structural heat capacity smooths or sharpens the temperature swing — watch the live temperature readout, the satellite's colour, and the scrolling temperature-history chart track the balance orbit after orbit. Drag to pan the view and scroll to zoom.