The Hohmann Orbit Transfer

Computes characteristics for coplanar and non-coplanar Hohmann orbit transfers.

The coplanar circular orbit-to-circular orbit transfer was discovered by the German engineer Walter Hohmann in 1925 and described in his classic report, The Attainability of Celestial Bodies. The transfer consists of a velocity impulse on an initial circular orbit, in the direction of motion and collinear with the velocity vector, which propels the space vehicle into an elliptical transfer orbit. At a transfer angle of 180 degrees from the first impulse, a second velocity impulse or , also collinear and in the direction of motion, places the vehicle into a final circular orbit at the desired final altitude.

The impulsive assumption means that the velocity, but not the position, of the vehicle is changed instantaneously. This is equivalent to a rocket engine with infinite thrust magnitude. The Hohmann formulation is the ideal and minimum energy solution to this type of time-free orbit transfer problem.

This submission is a PDF document and MATLAB script for computing the delta-v and orbit transfer characteristics between two coplanar or non-coplanar circular orbits. This MATLAB script is valid for Hohmann transfers from a high initial circular orbit to a lower final circular orbit. It also handles the case of transfer to a mission orbit with higher orbital inclination.

This script will also perform a graphical primer vector analysis of the script solution.