A complete university course in astrodynamics, in twelve units. It starts from Newton's laws and the two-body problem and builds, one result at a time, to the methods used to design real missions: orbital elements and reference frames, Kepler's equation and propagation, manoeuvres and perturbations, Lambert's problem and launch windows, patched-conic design of interplanetary trajectories and gravity-assist tours, the three-body problem and Lagrange-point missions such as India's Aditya-L1, and finally missions to the outer planets and their moons — orbit insertion, moon tours, three-body orbits, landing, and low-thrust missions that orbit more than one world. Every equation is derived, and every method is implemented and verified in Python against real ephemerides and real missions.
Before Newton: four thousand years of watching the sky, from the clay tablets of Babylon to the observatories of Baghdad, Maragha and Samarkand. Read this before Lesson 1-1.
Newton's laws, universal gravitation, angular momentum and orbital energy
The equation of motion, its closed-form solution and the conic sections
Reference frames, the classical orbital elements and ground-track geometry
Celestial, terrestrial, local and planetary frames — and every road between them
Kepler's equation for every conic, universal variables, analytic and numerical propagation, and SGP4
The rocket equation, Hohmann and bi-elliptic transfers, plane changes and rendezvous
J₂, atmospheric drag, solar radiation pressure, third bodies and station-keeping
Hyperbolic orbits, interplanetary Hohmann transfers, launch windows and gravity assists
The two-point boundary-value problem, its solvers, and how mission designers find a window to another planet
Spheres of influence, departure and arrival hyperbolas, B-plane targeting, gravity assists and multi-flyby mission design
The restricted three-body problem, the five Lagrange points, halo orbits, transfers and station-keeping, and India’s Aditya-L1 solar observatory
Gravity-assist routes to the giant planets, orbit insertion, moon tours, three-body orbits, landing, and low-thrust missions to more than one world