vlakir/AWP

Astrodynamics with Python, Spacecraft trajectory and attitude modeling and simulation, accompanied by YouTube videos

AWP - Astrodynamics with Python

• Video Explaining How To Use This Repository

The GitHub repository corresponding to the YouTube channel (https://www.youtube.com/AlfonsoGonzalezSpaceEngineering), which contains the following video series:

• Space Engineering Podcast
• Orbital Mechanics with Python
• Fundamentals of Orbital Mechanics
• Mecánica Orbital con Python
• Spacecraft Attitude Control with Python
• Numerical Methods with Python

Dependencies

• Python 3.0+
• SciPy
• Matplotlib
• SpiceyPy (SPICE Python Wrapper)
• pytest

Installing Python dependencies

Python packages can be easily and conviniently installed using pip via the command line like so:

$ python3 -m pip install {package_name}

In the case of AWP, all Python dependencies can be installed in one command using the requirements.txt file as so:

$ python3 -m pip install -r requirements.txt

Setting the PYTHONPATH and AWP Environment Variables

In order to use this repository path independently (can run any script from any directory), one must set the PYTHONPATH and AWP variables as the following:

• PYTHONPATH: Absolute path to your python_tools directory

# Two examples of how to set the PYTHONPATH variable

$ export PYTHONPATH=$PYTHONPATH:/home/alfonso/AWP/src/python_tools
# or
$ export PYTHONPATH=$PYTHONPATH:~/AWP/src/python_tools

• AWP: Absolute path to the base of this repository

# Two examples of how to set the AWP variable

$ export AWP=/home/alfonso/AWP
# or
$ export AWP=~/AWP

For convenience, these commands can be placed in a .bashrc file and thus will be automatically set anytime a new terminal session is begun.

Running Example Usages

Once the dependencies are installed and environment variables are set, the example usage cases can be run (from the base path of this repository):

# ensure you are in the base path of this repository
$ pwd
/home/alfonso/AWP
# run the example usages
$ python3 example_usage/Spacecraft_hello_world.py
$ python3 example_usage/many_orbits.py

Running Unit Tests

Again, once dependencies are installed and environment variables set, the unit tests can be run with the following command (from the base path of this repository):

# ensure you are in the base path of this repository
$ pwd
/home/alfonso/AWP
# run the unit tests using one of the following commands
$ pytest src/python_tools/unit_tests/ -vv
# or
$ python3 -m pytest src/python_tools/unit_tests/ -vv

The only difference between those two commands is that running pytest through the Python interpreter is that python will add your current directory to sys.path