For a long time, I've wanted to understand the fundamentals of orbital mechanics and in doing so, I though I would create a tool to help visualize simple one-body (eventually two-body 🙂) orbits given their Keplarian orbital parameters, or geocentric position and velocity vectors. This tool allows you to adjust those parameters and watch how it affects others, and the overall orbit dynamically.
If you're using nodenv, simply type nodenv install to grab node v12.13.0, then run npm install to fetch express.js. Once you have the right version installed, simply run npm start and use your browser to visit localhost:3001