Spacecraft Dynamics

A Python package developed from various courses, assignments and projects.

Features

• Modeling of satellite attitude dynamics
• Support for various kinds of actuators
  • Reaction wheels
  • Variable-Speed Control Moment Gyroscopes (VSCMGs)
  • None (control authority is assumed)
• Support for different control algorithms
• Support for different guidance algorithms
• Relative motion dynamics modeling (for formation flying and collision avoidance uses)

Coming Soon

• Guidance algorithms as the primary interface to the satellite (this is how most 3rd party software uses an ADCS!)
• Combining orbit propagation and formation flying dynamics with rotational dynamics
  • Currently these things are somewhat decoupled (a full pos/vel/att/angVel sim can be constructed right now but it'd be annoying)
  • Some of the example scenarios fake orbit prop by converting propagating spherical coordinates over time and converting them to cartesian (no equations of motion are actually modeled though)

Installation

This package is not on PyPI but you can install it directly from the repository:

# Clone the repository
git clone https://github.com/Jmiceli17/spacecraft_dynamics.git
cd spacecraft_dynamics

# Upgrade setuptools to support editable installs
pip install --upgrade setuptools>=64.0

# Option 1: Install directly
pip install .

# Option 2: Install in development mode (if you want to modify the code)
pip install -e .

Documentation

See https://github.com/Jmiceli17/spacecraft_dynamics/tree/main/docs for this package's current documentation.

Examples

See the examples/ directory for usage examples:

• Attitude control simulations
• Actuator configurations
• Orbital scenarios
• Scripts that demonstrate how to use certain classes and utility functions (developed for various quizzes and homeworks)

# Example usage
cd spacecraft_dynamics/examples
python mission-simulation.py

Note: If running in WSL2, you may need to:

1. Install and start XLaunch/VcXsrv (or some other X-server)
2. Set the DISPLAY environment variable: export DISPLAY=:0 (or export DISPLAY=$(cat /etc/resolv.conf | grep nameserver | awk '{print $2}'):0 for WSL2)
3. Ensure tkinter is available: conda install tk or apt-get install python3-tk (if using system Python)

The plotting code will automatically detect if a display is available and use an appropriate backend.

Example Visualizations

Attitude Reference Tracking

Attitude Control Simulation with VSCMG Null Motion

Package Structure

spacecraft_dynamics/
├── src/spacecraft_dynamics/
│   ├── actuators/      # Reaction wheels, VSCMGs
│   ├── control/        # Control algorithms
│   ├── core/           # Core spacecraft models
│   ├── guidance/       # Guidance algorithms
│   ├── orbit/          # Orbital dynamics
│   ├── state/          # State representations
│   ├── utils/          # Utility functions
│   └── analysis/       # Plotting and analysis tools
├── examples/           # Example simulations
└── docs/               # Documentation

Development

For development, clone the repository and create a conda (recommended) environment:

git clone https://github.com/Jmiceli17/spacecraft_dynamics.git
cd spacecraft_dynamics
conda env create -f environment.yml
conda activate sc-dyn

# Upgrade setuptools to support editable installs (PEP 660)
pip install --upgrade setuptools>=64.0

pip install -e .

License

This project is licensed under the MIT License - see the LICENSE file for details.