Gravity Perturbed Optimal Orbital Transfer Analysis - SNOPT

Optimal two impulse transfer subject to non-spherical gravity perturbations

MATLAB script named poota_snopt which can be used to solve the optimal two-impulse, non-spherical gravity perturbed orbital transfer between non-coplanar Earth orbits. The algorithm initializes with a two-body initial guess for the orbital transfer and uses the SNOPT nonlinear programming (NLP) method to determine the optimum two impulse orbit transfer subject to non-spherical Earth gravity perturbations. Additional orbit perturbations such as third-body point mass gravity, aerodynamic drag or solar radiation pressure can easily be added to the equations of motion of this MATLAB script.

The poota_snopt script uses modified equinoctial orbital elements to solve the gravity perturbed orbit transfer “targeting” problem. Additional information about these orbital elements along with techniques for trajectory modeling can be found in Appendix A. That appendix also explains how to use components and combinations of these non-singular elements to calculate a variety of final orbital element targets or boundary conditions.

Information about MATLAB versions of SNOPT for several computer platforms can be found at Professor Philip Gill’s web site which is located at http://ccom.ucsd.edu/~optimizers/. Professor Gill’s web site also includes a PDF version of the SNOPT software user’s guide. A brief introduction to nonlinear programming can be found in Appendix C of the user's manual.