Orbital Mechanics

Set of Orbital Mechanics functions transcribed from MATLAB or textbooks in Python to support larger Orbital Mechanics projects and classes. Check out the official Pypi upload here!

image source: Wikipedia

Installation

Method 1: Pip

Run the following command in the command line to install the library via pip:

pip install cpslo_orbits

Check to make sure it was installed with the following command:

pip list

Method 2: Local Installation

To install a local copy e.g., for development clone the repository in the directory of your choosing:

git clone https://github.com/gagandeepthapar/OrbitalMechanics.git

and install the required libraries from the requirements.txt file:

pip install -r requirements.txt

and install the library locally:

pip install -e .

Ensure the library is installed by running pip list or by running pytest:

cd tests/
pytest

Pytest should run and indicate the failed/passed tests. Note: some tests may fail as there is ongoing development to create thorough test cases for each method presented in this module.

Structure

The repository is broken up into 4 main packages:

• orbitalcore (Basic Orbital Mechanics)
• relativemotion (Rendezvous/Relative Motion Mechanics)
• perturbations (Perturbational Effects)
• observations (Observations/Filtering)

This structure closely follows the breakdown of the Orbital Mechanics path at California Polytechnic State University - San Luis Obispo: AERO 351 (Basic Orbital Mechanics), AERO 452 (Rendezvous/Relative Motion, Perturbational Effects), and AERO 557 (Observations/Filtering, Optimal Transfer).

Approach

The approach in building this repository was to avoid using unnecessary classes and containers to minimize the learning curve and to provide the simplest form of usability for students and faculty. That being said, NumPy and MatPlotLib are heavily used throughout the repository to enable the math to be simply executed. Many optimization opportunities were not taken to minimize confusion and enable users to peek into the source code and understand what is happening.

Extending the Package

I hope students will continue to add on to this package and improve usability for the curriculum. My intentions were to provide resources (e.g., pointing to specific textbooks/algorithms) for people to refer back to and ensure the code is very readable.

Extensions/additional functions should always include type-hinting in the arguments and return statement and should include docstrings at the top of each function for context. The function docstring should include the purpose, where the function is adapted from (e.g., "Orbital Mechanics for Engineering Students", Curtis), and the explanations for each input and return argument.

Do as I say and not as I do and use proper git-techniques by creating branches from main to develop features/fixes and pulling into main as opposed to developing everything directly in main.

Organize the package thoughtfully. Only put core methods in orbitalcore, perturbations in perturbations, etc. If a method is sufficiently unique then feel free to create a new module e.g., for optimal orbit transfers.