Eclipse duration (circular)

Order-of-magnitude umbra time for circular orbit (cylindrical shadow, coplanar worst case).

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

Formula

t_ecl ≈ T β/π (cylindrical shadow)

Circular-orbit eclipse estimate

Primary sources

Fundamentals of Astrodynamics and Applications (David A. Vallado): Standard reference for two-body, Lambert, maneuvers, and J2. Equations implemented independently in SIDUS.
Orbital Mechanics for Engineering Students (Howard D. Curtis): Textbook derivations for Hohmann, vis-viva, rocket equation, elements.
Space Mission Engineering: The New SMAD (Wertz, Everett, Puschell (eds.)): Mission engineering handbook: RF links, constellations, and ops framing.

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.

Open interactive tool · SIDUS