Libraries & Toolkits

A mature, low-level space-flight-dynamics library in Java (with Python bindings) providing high-precision orbit propagation, attitude modelling, time and frame transformations, and maneuver planning. Orekit is used in professional mission analysis and operations for its accuracy and breadth.

A Python library for interactive astrodynamics and orbital mechanics — defining orbits, propagating them, and planning maneuvers — built on Astropy's units and time handling. Its active development is now archived, with the work continuing in a successor library, but it remains a well-known tool for orbit computations.

A Python library for computing precise positions of stars, planets, and satellites as seen from any point on the Earth or in space, using the same JPL ephemerides and reference frames as professional astronomy. Skyfield is a popular modern tool for accurate, easy positional astronomy.