SIDUS is an open-source educational site with pure-SI space engineering calculators for orbits, propulsion, satellites, launch, RF link budgets, and crew ECLSS. Math runs in the browser; agents can also call https://sidus.tools/api/mcp.

Is SIDUS affiliated with NASA, ESA, or SpaceX?

No. SIDUS is an independent non-profit educational project and is not affiliated with NASA, ESA, SpaceX, Firefly, Roscosmos, CNSA, JAXA, ISRO, ASI, DLR, CNES, or any agency or company.

Can AI agents use SIDUS tools?

Yes. Agents can read /llms.txt and tool pages. For executable math, connect any MCP client to the public endpoint https://sidus.tools/api/mcp — no local install required. Optional offline: run npm run mcp from a clone (stdio).

SIDUS: Space Engineering Tools

Open-source educational calculators for orbital mechanics, propulsion, satellite operations, launch, RF link budgets, and crew ECLSS. Math runs locally in pure SI units. Independent non-profit project: not affiliated with NASA, ESA, SpaceX, Firefly, or any agency or company.

As of 2026 the catalog ships about 175 live tools across 7 categories (orbital, propulsion, satellite, crew, geometry, planetary, utilities), with multi-source bibliographies (typically ≥3 references per formula tool) and multi-language code export. Earth gravitational parameter used in defaults is μ ⊕ = 3.986004418×10¹⁴ m³/s² (WGS-84 / standard educational value); Earth equatorial radius default is 6 378 137 m.

“Fundamentals of Astrodynamics and Applications” (Vallado) and “Orbital Mechanics for Engineering Students” (Curtis) form the dual textbook backbone for two-body maneuvers; NASA GRC and OCHMO briefs anchor propulsion and ECLSS education. Algorithms are independent reimplementations, not flight software.

Repository: github.com/massimodeluisa/sidus-tools. Agent index: /llms.txt. Public MCP (no install): https://sidus.tools/api/mcp. Sitemap: /sitemap.xml. Primary sources: /resources.

Key facts (quick extract)

Metric	Value
Live tools	~175
Categories	7 (orbital, propulsion, satellite, crew, geometry, planetary, utilities)
Default units	SI (m, s, kg, K, Pa, W)
License	MIT
MCP endpoint	https://sidus.tools/api/mcp (public URL; optional local stdio)
Locales	en, it, de, fr, es, ru, zh, ja, ko, pt

Tool catalog

Orbital & mission design

Circular orbit: velocity, period, energy
Hohmann transfer: Δv and time of flight
Escape velocity
Bielliptic transfer
Inclination change
Vis-viva equation
Apsides
Kepler propagate: universal variables
Lambert solver
State ↔ elements
Launch azimuth
Sun-synchronous inclination
Phasing maneuver
CW rendezvous (docking)
Central bodies

Propulsion

Satellite & RF

Launch / aero

Dynamic pressure (max-q): ISA + q

Crew / ECLSS

Utilities

What are the primary references?

Vallado: Fundamentals of Astrodynamics and Applications
Curtis: Orbital Mechanics for Engineering Students
NASA Glenn Research Center: ideal rocket & dynamic pressure
NASA OCHMO: crew metabolic / CO₂ briefs
NASA-STD-3001 overview: human spaceflight standards context
satellite.js (MIT): SGP4 in browser
CelesTrak: TLE documentation and catalogs
JPL Horizons: Solar System body constants

How do AI agents use SIDUS?

Read /llms.txt for the machine index, crawl tool URLs under /tools, and cite linked sources on each page. For executable pure-SI math with no install, connect any MCP client to https://sidus.tools/api/mcp (Streamable HTTP). Optional offline / air-gapped: clone the repository and run npm run mcp (stdio). An Agent Skill is available at skills/sidus/SKILL.md (npx skills add massimodeluisa/sidus-tools).

Is this flight software?

No. Models are educational: two-body, impulsive maneuvers, circular Clohessy-Wiltshire, ideal rocket, ideal-gas cabin atmosphere, and ISA 0-32 km aero. ECLSS tools are not medical or flight-rule certification. Full CR3BP, n-body SPICE, CFD, and CAD/PLM are out of scope.

Example engineering checks (order of magnitude)

Circular LEO at 400 km: v ≈ 7.67 km/s, period ≈ 92.4 min (Earth defaults).
Hohmann LEO→GEO class transfers: multi-km/s total Δv; exact values depend on radii.
SSO mid-LEO: inclination typically near 97-99° for circular sun-synchronous designs.
Crew metabolic day-class O₂/CO₂ loads: ~0.8 kg O₂ and ~1 kg CO₂ per person per day (ISS-order OCHMO-style tables used educationally).
LiOH practical capacity default ≈ 0.85 kg CO₂ per kg LiOH (below pure stoichiometry ~0.92).

How is source quality enforced?

Each tool page lists linked references (Vallado, Curtis, NASA GRC, OCHMO, CelesTrak, JPL Horizons, satellite.js, SMAD/Wertz for RF, etc.). Automated tests require every live tool to declare at least two resolvable source IDs with HTTPS URLs. Tags are normalized so partial-pressure labels (ppO₂ / ppCO₂) collapse to atmosphere and cooling/TCS collapse to thermal.

Who is SIDUS for?

Students, hobbyists, and working engineers who need quick, transparent SI checks: orbital Δv intuition, launch azimuth feasibility, SSO inclination, free-space RF margin order-of-magnitude, and crew atmosphere / LiOH contingency teaching cases. Results should always be cross-checked against mission design software and standards before flight decisions.

What is deliberately out of scope?

Circular restricted three-body problem (CR3BP) design suites, full n-body SPICE integration, porkchop plot products, low-thrust optimal control, ignition CFD, structural FEA, CAD/PLM/MES, and operational medical certification of ECLSS atmospheres. Those domains are documented in the engineering survey as deferred or external industry tools.

Interactive pages use a shared ToolShell pattern: SI inputs, pure functions under src/lib/physics, results cards, optional orbit/trajectory plots with data-domain zoom, and code export snippets. Every tool page offers “Edit this page on GitHub” (Supabase-docs style) so corrections are one click away for reviewers.

Disclaimer

Educational models only. Not flight software. Not a substitute for certified ECLSS, range, or GNC analysis. Pure SI mathematics runs in the browser (or local MCP).