Spherical distance
Great-circle range, central angle, and initial bearing on a spherical body (spherical law of cosines).
SIDUS educational calculator. Category geometry. Tags: geometry, GNC, mission-design, trigonometry. Pure SI. Not flight software.
Formula
cos c = sin φ₁ sin φ₂ + cos φ₁ cos φ₂ cos Δλ
Great-circle distance on a sphere
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.
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.