SIDUS

SIDUS: educational space-engineering calculators

I am a software engineer, not a space engineer, but I am passionate about space engineering. That is why I built sidus.tools.

SIDUS (sidus, Latin for constellation) is a free, open-source set of educational calculators for orbital mechanics, propulsion, satellite ops, launch, RF link budgets, and crew ECLSS. About 175 tools. Pure SI. MIT. They run in the browser. No account.

The point is a fast SI check you can actually see: inputs, the formula, the result, optional plots, and Edit this page on GitHub. Defaults use educational WGS-84-class Earth values (μ⊕ = 3.986004418×10¹⁴ m³/s², equatorial radius 6 378 137 m). Models stay small on purpose: two-body, impulsive burns, circular Clohessy-Wiltshire, ideal rocket, ISA aero.

Formula pages carry a bibliography (Vallado and Curtis as the two-body backbone, plus NASA-class references where they apply). Automated checks want real HTTPS source URLs before a tool ships.

The same catalog is on a public MCP at https://sidus.tools/api/mcp (Streamable HTTP). You point a client at that URL. No clone. Agent Skill, if you want it that way: npx skills add massimodeluisa/sidus-tools --skill sidus.

If you want the same number in your own stack, pages can export code (C, C++, Rust, Zig, Python, JS/TS, MATLAB, Julia, Fortran, LaTeX). The formulas and that exportable / executable code should be reviewed and tested.