Sphere of influence

Laplace SOI radius r ≈ a (m/M)^(2/5) for patched-conic teaching.

SIDUS educational calculator. Category orbital. Tags: mission-design, orbital, reference, trajectory. Pure SI. Not flight software.

Formula

r_SOI ≈ a (m/M)^{2/5}

Patched-conic sphere of influence

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.
JPL Horizons (NASA / JPL): Solar System ephemerides and body constants.

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