Is this flight software?

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

Orbit from period

Semi-major axis, altitude and speed for a target orbital period.

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

a³ = μ T²/(4π²)

Orbit from target period

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.
SIDUS pure-SI implementation (sidus.tools): Local pure-function implementations in src/lib/physics (educational, independent reimplementation).

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