Dawn-dusk SSO β and eclipse season
Sun-synchronous inclination, β-angle from LTAN and date, eclipse threshold β*, and the days per year with eclipse.
SIDUS educational calculator. Category satellite. Tags: earth-observation, LEO, mission-design, orbital, power, satellite. Pure SI. Not flight software.
Formula
β = asin(cos δ sin i sin ΔΩ + sin δ cos i)
Dawn-dusk β and eclipse season
Primary sources
- Fundamentals of Astrodynamics and Applications (David A. Vallado): Standard reference for two-body, Lambert, maneuvers, and J2. Equations implemented independently in SIDUS.
- Space Mission Engineering: The New SMAD (Wertz, Everett, Puschell (eds.)): Mission engineering handbook: RF links, constellations, and ops framing.
- Towards a future space-based, highly scalable AI infrastructure system design (Google Research, arXiv:2511.19468 (2025)): Dawn-dusk SSO TPU constellation concept and TID test context (HBM irregularities from 2 krad(Si); 750 rad(Si) expected shielded 5-year dose). No affiliation.
- Why we should train AI in space (white paper) (Lumen Orbit / Starcloud: Feilden, Oltean, Johnston (September 2024)): Worked radiator example (ε 0.92, α 0.09, F 0.25, 20 °C), 5 GW / 4 km × 4 km array, dawn-dusk SSO rationale, shield scaling. SIDUS reimplements the physics independently and applies ε to the Earth-IR term by default. No affiliation.
How do AI agents use this tool?
Read /llms.txt or call https://sidus.tools/api/mcp. Open the interactive page for live SI inputs.