Brahe - easy-to-learn, high-performance, and quick-to-deploy

Documentation: https://duncaneddy.github.io/brahe

Rust Library Reference: https://docs.rs/crate/brahe/latest

Source Code: https://github.com/duncaneddy/brahe

Overhaul Notice

The older pure-Python version of brahe is currently being deprecated in favor of a mixed Rust-Python implementation, along with improved documentation. That means that the development on the master branch is being frozen and will no longer be developed against. Moving forward the main branch will be the primary branch for the project.

There will be point commits (less than 1.0.0) during this period as part of improving the CI/CD workflow for the project. Furthermore, initially the features of the new implementation will not be at partity with the old python implementation, so users should pin their requirements file to use the latest commit of the master branch:

brahe @ git+https://github.com/duncaneddy/brahe@master

To install and use the latest master branch via pip

pip install git+https://github.com/duncaneddy/brahe.git@master

The old master branch can be found here.

Brahe

Brahe is a modern satellite dynamics library for research and engineering applications. It is designed to be easy-to-learn, high-performance, and quick-to-deploy. The north-star of the development is enabling users to solve meaningful problems and answer questions quickly, easily, and correctly.

The key features of the library are:

• Intuitive API: API designed to be easily composable, making it easy to solve complex problems correctly by building on core functionality.
• Easy-to-Learn: Designed to be easy to use and learn. The objective is to provide clear documentation and visibility into what the software is doing so that users don't need to spend time reverse engineering internal routines and more time solving their own problems.
• High-Performance: Brahe provides a Python 3.6+ wrapper that is auto-generated from a core Rust library. This provides fast core implementation, while allowing users to take advantage of Python's rich scientific ecosystem if they so choose.
• Answer Questions Quickly: Brahe is designed to make it easy to code up solutions to meaningful problems. High-fieldity, high-performance APIs are not the end-objective, but helping users solve their problems.

Brahe gets its name from the combination of Rust and astrodynamics (Rust + astrodynamics = Brahe). The library specifically focuses on satellite astrodynamics and space mission analysis. While the underlying concepts have been studied and known since Kepler wrote down his three laws, there are few modern software libraries that make these concepts easily accessible. While extremely well tested, other astrodynamics and mission analysis software can have an extremely steep learning curve, making it difficult to quickly run simple analysis that is known to be correct.

Because of this, students, researchers, and engineers frequently end up reimplementing common astrodynamics and mission analysis tools with unfortunately frequent regularity. While reimplementation of common code can be a good learning mechanisms, in most cases it is both error-prone and costs time better spent on other endeavours. This project seeks to providing an easy-to-use, well-tested library, to enable everyone to more easily, and quickly perform astrodynamics and space mission analysis without sacrificing performance or correctness. The software built in Rust for performance with bindings to Python for ease of use.

The implementation approach is opinionated, the objective is to provide an easy-to-use and accurate astrodynamics library to enable users to quickly and correctly solve most common problem types. it is not practical to try to implement every aerodynamics model and function utilized in practice or historically. Since Brahe is open source, if a specific function is not present, or a different implementation is required, users can modify the code to address their specific use case. This means that Brahe, while we want to continue expanding the capabilities of the module over time, the immediate goal is to provide a well-tested, flexible, composable API to quickly address modern problems in astrodynamics.

One example of this in practice is that the built-in Earth reference frame transformation utilizes the IAU 2006/2000A precession-nutation model, CIO-based transformation. Even through there are multiple ways to construct this transformation, Brahe only implements one. Another example, is that the geodetic and geocentric transformations use the latest NIMA technical report definitions for Earth's radius and flatness. If a desired model isn't implemented users are free to extend the software to address and functionality or modeling gaps that exist to address their specific application.

Documentation

You can find the package documentation here. This documentation is meant to provide a human-friendly walk through of the software and package. Brahe is currently in the early stages of development so the documentation will likely not be complete. Sections marked [WIP] will have some software functionality implemented but not be considered documented.

The most complete API reference guide will always be the Rust crate API reference, found on crates.io. This is always up-to-date with the latest release since it is autogenerated at build time during the release process.

Software Usage and License

The Brahe package is licensed and distributed under an MIT License to encourage adoption and to make it easy to integrate with other tools.

The only thing asked is that if you do use the package in your work, or appreciate the project, either send a message or star the project. Knowing that the project is being actively used is a large motivator for continued development.

Support and Acknowledgement

Brahe is currently being developed primarily for my own enjoyment and because I find having these tools helpful in professional and hobby work. I plan to continue developing it for the time being regardless of greater adoption as time permitting.

That being said, it's incredibly encouraging and useful to know if the software is being adopted or found useful in wider practice. If you're using Brahe for school, research, or a commercial endeavour, I'd love to know about it! Tweet me @duncaneddy or email me at duncan.eddy (at) gmail.com.