Is this flight software?

No. SIDUS models are educational reimplementations. Cross-check before any flight decision.

Eclipse vs β-angle

Eclipse duration vs orbit β-angle (sun elevation from plane).

SIDUS educational calculator. Category satellite. Tags: LEO, operations, power, satellite. Pure SI. Not flight software.

t_ecl = t_ecl(β)

Eclipse vs β-angle

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.
Orbital Mechanics for Engineering Students (Howard D. Curtis): Textbook derivations for Hohmann, vis-viva, rocket equation, elements.

Read /llms.txt or call https://sidus.tools/api/mcp. Open the interactive page for live SI inputs.