# Orbital Simulator A fast N-body orbital mechanics simulator written in Rust with Python visualization tools. Simulate planetary motion using Newtonian gravity with configurable parameters and create animations of the results. ## Features - N-body gravitational simulation with normalized units - Configurable mass, distance, and time scales - JSON and TOML configuration support - Binary trajectory output format - 2D and 3D trajectory plotting - Animated simulations with customizable reference frames - Energy conservation analysis - Video export (requires ffmpeg) - Pre-built configurations for solar system scenarios ## Installation You'll need Rust (2021 edition or later) and Python 3.7+. For video export, install ffmpeg. ```bash git clone cd orbital_simulator cargo build --release pip install -r requirements.txt ``` ## Quick Examples Simulate the inner solar system for one year: ```bash cargo run --release --bin simulator -- \ --config config/inner_solar_system.toml \ --time 365d \ --step-size 3600 \ --output-file solar_system.bin python3 plot_trajectories.py solar_system.bin --animate ``` Or try a simple Earth-Sun system: ```bash cargo run --release --bin simulator -- \ --config config/earthsun_corrected.toml \ --time 30d \ --step-size 3600 \ --output-file earth_sun.bin python3 plot_trajectories.py earth_sun.bin --animate --center Earth ``` ## Configuration Configuration files define the initial state of your celestial bodies: ```toml [[bodies]] name = "Sun" mass = 1.989e30 position = [0.0, 0.0, 0.0] velocity = [0.0, 0.0, 0.0] [[bodies]] name = "Earth" mass = 5.972e24 position = [1.496e11, 0.0, 0.0] # 1 AU from Sun velocity = [0.0, 29789.0, 0.0] # Orbital velocity # Optionally specify custom units [normalization] m_0 = 5.972e24 # Earth mass r_0 = 6.378e6 # Earth radius t_0 = 5023.0 # Time unit ``` Several configurations are included: - `planets.toml` - Complete solar system (16 bodies) - `solar_system.toml` - Major planets only (9 bodies) - `inner_solar_system.toml` - Inner planets + Moon (6 bodies) - `earthsun_corrected.toml` - Simple Earth-Sun system (2 bodies) ## Usage ### Running Simulations ```bash cargo run --bin simulator -- [OPTIONS] ``` Key options: - `-c, --config ` - Configuration file - `-t, --time ` - How long to simulate (e.g., 10s, 5m, 2h, 100d) - `-s, --step-size ` - Integration step size (default: 10.0) - `-o, --output-file ` - Where to save trajectory data - `-w, --force-overwrite` - Skip confirmation when overwriting files ### Visualization ```bash python3 plot_trajectories.py [OPTIONS] ``` Useful options: - `--animate` - Show animated trajectories instead of static plots - `--center ` - Center the view on a specific body - `--save-animation ` - Export animation as MP4 video - `--energy` - Include energy conservation plots - `--list-bodies` - Show what bodies are in the trajectory file - `--2d-only` or `--3d-only` - Limit to 2D or 3D plots ### Examples ```bash # See what bodies are available python3 plot_trajectories.py trajectory.bin --list-bodies # Animate from different perspectives python3 plot_trajectories.py trajectory.bin --animate --center Sun python3 plot_trajectories.py trajectory.bin --animate --center Jupiter # Create a video python3 plot_trajectories.py trajectory.bin --animate --save-animation solar_system # Check energy conservation python3 plot_trajectories.py trajectory.bin --energy ``` ## How It Works The simulator uses Newtonian gravity (F = G·m₁·m₂/r²) with explicit Euler integration. All bodies interact gravitationally with each other. The system normalizes units to Earth-based scales by default but you can specify custom normalization constants. Animations automatically scale to about 60 seconds and show the time compression ratio (like "3.6 hours of simulation per second"). You can center the view on any body to see orbital mechanics from different reference frames. The simulator includes safety features like confirmation prompts before overwriting files, and exports data in an efficient binary format. ## Project Structure ``` src/ ├── bin/ │ ├── simulator.rs # Main simulation program │ └── orbiter.rs # 3D visualizer ├── config.rs # Configuration loading ├── simulation.rs # Physics simulation ├── types.rs # Data types and units └── lib.rs # Library interface config/ # Pre-made configurations plot_trajectories.py # Visualization script inspect_trajectories.py # Data inspection tool ``` ## License MIT License - see source for details. ## Author Thomas Faour