The line between day and night.
A dawn–dusk orbit is sun-synchronous: Earth's equatorial bulge turns the orbit plane once a year, so it stays aligned with the boundary between day and night.
Satellite InferenceAI Inference in OrbitGet in touch ORBIT SIMULATOR / PHYSICS MODEL
See why the orbit
matters.
Pick an orbit and a date, or run a whole year. The simulation follows a spacecraft through Earth's shadow with real orbital geometry, and shows why our future solar compute nodes are designed for a dawn–dusk orbit.
Sunlight over the year96%
Longest shadow per orbit20 min
Days with any shadow90
Orbit period · inclination98 min · 98.0°
Sun-synchronous, ascending node at 18:00. Our model orbit for SI Nodes. Orbit plays one orbit in 12 seconds; Year plays the seasons in 40 seconds. Dashed orbit segments are in Earth's shadow; the amber trace is the ground track. Earth imagery: NASA Blue Marble and Black Marble.
Dawn–dusk, 650 km: 96% sunlight53° inclined, 550 km: 69% sunlightMid-morning, 550 km: 64% sunlight
01 / WHAT YOU ARE SEEING
Sunlight is a design choice.
A short eclipse season.
Press Year to watch it. Around the June solstice the tilt of Earth's axis turns the orbit plane toward the Sun line. When β, the angle between them, falls below about 65°, the orbit clips Earth's shadow: up to about 20 minutes per orbit, for roughly three months. Solar arrays and batteries are sized for that worst day.
Fewer kilograms per kilowatt.
More hours of sunlight per kilogram launched means fewer solar panels and batteries for the same compute: a direct input to the cost of an orbital GPU-hour. Size a node to see the arrays, battery and radiators.
02 / METHOD AND LIMITS
Real geometry, screening accuracy.
Circular two-body orbits with J2 nodal precession, a low-precision solar ephemeris for 2027 and a cylindrical Earth shadow without penumbra or atmospheric refraction. The annual results match the Satellite Inference orbit model v3.1 to within half a percentage point; automated tests check this on every build.
A communication tool, not mission analysis. The SI-P1 pathfinder flies in its host's orbit; the dawn–dusk orbit applies to future SI Nodes. Altitude is drawn to scale. Earth imagery: NASA Blue Marble Next Generation and NASA Black Marble 2016 (NASA Earth Observatory), lit by the modeled Sun; clouds and seasonal snow are not modeled.