LunCoSim is an open-source, collaborative digital twin of the solar system. Built for high-fidelity space mission planning, engineering, and training, it enables multiple participants to design and operate complex systems in a shared 3D environment.
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Empowering everyone to architect the future of space, LunCoSim delivers professional-grade simulation fidelity at every scale—from individual rovers to entire lunar cities—through five core technological pillars:
Real-time collaborative engineering where multiple participants interact in the same high-fidelity environment. Whether you are driving a rover, monitoring telemetry, or managing orbital maneuvers, the simulation remains synchronized and authoritative.
We leverage Universal Scene Description (USD) for 3D world composition. This ensures industrial-grade interoperability with Pixar USD and NVIDIA Isaac Sim, allowing you to author once and simulate everywhere.
Native integration of Modelica provides high-fidelity 2D and 3D realistic engineering physics simulation for critical subsystems. Compute the power draw, thermal rejection, and life support levels with professional-grade, rigorous and interpretable mathematical models.
We use the next-generation SysML v2 standard as our structural blueprint. Every entity and its state is defined by an engineering model, serving as the ultimate "Source of Truth" for the simulation.
Monitor your missions using the XML Telemetry and Command Exchange (XTCE) standard. Compatible with professional tools like YAMCS and NASA OpenMCT, LunCoSim provides real-time, standardized hardware telemetry.
- Desktop & Browser Support: High-performance native execution on Linux/Windows and accessible via web browsers (links coming soon).
- Headless-First Architecture: Core simulation logic is decoupled from rendering, enabling high-speed automated validation and massive parallel Monte Carlo analysis.
- Planetary Precision (f64): All spatial math and physics use double-precision floating point (f64) for absolute stability across the scales of a lunar base or the entire solar system.
- Hotswappable Plugins: A highly dynamic architecture where every feature — from flight software to physics integrators — is a modular plugin that can be swapped without a restart.
- In-Scene Editing: Spawn rovers, props, and terrain directly in the running simulation. Transform and inspect objects with gizmo tools.
- Rust Toolchain (Stable)
- Git
Clone the repository and run the simulation sandbox:
git clone https://github.com/LunCoSim/lunco-sim.git
cd lunco-sim
cargo run --release -p lunco-client --bin rover_sandboxThe USD-based rover sandbox loads the entire scene — rovers, terrain, and camera — from declarative .usda files. It includes an in-scene editing toolkit:
cargo run --release -p lunco-client --bin rover_sandbox_usdEditing Tools:
- Spawn Palette — Click or drag rovers, balls, ramps, and walls into the scene
- Transform Gizmo — Select objects and use G (translate) / R (rotate) to manipulate them
- Inspector Panel — View entity parameters (position, mass, physics)
- Undo — Ctrl+Z to revert spawns and moves
- Escape — Cancel current operation
See USD System Documentation for rover definitions, scene composition, wheel types, and the full editing tools architecture.
LunCoSim is built as a modular multi-crate workspace:
lunco-core: Headless simulation core, CommandMessage architecture, and base traits.lunco-celestial: Planetary mechanics, SOI handling, and environments.lunco-mobility: Rover locomotion — differential drive, Ackermann steering, raycast suspension.lunco-fsw: Flight software — digital ports, wires, and subsystem logic.lunco-avatar: User presence, camera modes (freeflight, orbit, spring arm), and possession.lunco-controller: Input translation — keyboard/intent to CommandMessage.lunco-sandbox-edit: In-scene editing — spawn palette, transform gizmo, inspector, undo.lunco-usd: USD integration — 3-plugin pipeline for visual, physics, and simulation mapping.lunco-client: Visual desktop client — combines all subsystems into the sandbox binary.lunco-modelica: Modelica simulation — AST-based parsing, component diagrams, workbench UI.lunco-ui: Reusable UI mechanisms — WidgetSystem, node graphs, 3D world-space UI.lunco-attributes: Reflection-based attribute system for SysML v2 alignment.
All UI panels are entity viewers — they watch a selected entity and render its data. The same panel works in a standalone workbench, a 3D overlay, or a mission dashboard.
Entity (ModelicaModel, FswConfig, etc.)
│
┌──────────────────┼──────────────────┐
▼ ▼ ▼
DiagramPanel CodeEditorPanel TelemetryPanel
(egui-snarl) (text editor) (params/inputs)
WorkbenchState.selected_entity is the selection bridge — any context (library browser, 3D viewport click, colony tree) can set it to open the editor for any entity.
Panels are dockable, tabbable, resizable, and persist across sessions:
| Panel | Position | Purpose |
|---|---|---|
| Library Browser | Left dock | File navigation, drag .mo files |
| Code Editor | Center tab | Source code editing, compile & run |
| Diagram | Center tab | Component block diagram (egui-snarl) |
| Telemetry | Right dock | Parameters, inputs, variable toggles |
| Graphs | Bottom dock | Time-series plots |
See UI/UX Architecture Research for the full analysis of professional tools and our design decisions.
For those interested in the deep technical details, future architecture, and granular implementation plans, we maintain a comprehensive set of specifications in the specs/ directory.
The original Godot 4 implementation of LunCoSim is still available on the main-godot4 branch.
Want to contribute? We follow a strict TDD and Documentation mandate. Apply here to join our team! Check our Principles and Detailed Specifications to understand our core principles and roadmap.