Astropy

The community-developed core Python package for astronomy, coordinates, time, units, tables, and scientific data.

SPICE-enhanced Cosmographia

A free NASA/JPL mission-visualization application for SPICE-driven trajectories, attitudes, instruments, and observation geometry.

NASA/JPL SPICE Toolkit

NASA/JPL’s free toolkit and data system for mission geometry, ephemerides, observation planning, and science operations.

SatNOGS

An open-source global satellite ground-station network, client stack, and public transmitter database.

Skyfield

A production-stable MIT-licensed Python library for precise positions of planets, stars, and Earth satellites.