Modeling a Finite-burn Trans-lunar Injection Maneuver

MATLAB script for modeling a constant thrust, constant specific impulse, finite-burn trans-lunar injection maneuver from Earth orbit.

This submission is a MATLAB script named demo_tlto that demonstrates how to model a finite-burn trans-lunar trajectory maneuver. The maneuver is performed with a constant thrust and constant specific impulse propulsion system. The optimal flight controls (inertial unit thrust vector) for this script can be determined using a FORTRAN program named tlto_sos.

Additional information about the tlto_sos program can be found in Appendix B of this document.

The important features of this MATLAB script are as follows:

• Earth true-of-date coordinate system
• Cartesian equations of motion
• JPL DE430 planetary ephemeris
• Point-mass gravity perturbations of the Sun and Moon
• Non-spherical Earth gravity model

This script reads JPL planetary ephemerides in a machine-independent binary format which are available from the SPICE web site. These *.bsp ephemeris files are IEEE-Little Endian style of binary kernel. This is the binary form native to PC/Linux, PC/Windows and MAC/Intel machines. Additional information about JPL ephemerides can be found at http://naif.jpl.nasa.gov/naif/.

The demo_tlto script uses routines from the MICE software suite to read and evaluate the JPL binary ephemeris file. Platform-specific MICE mex files, support functions and the binary ephemeris files are available at naif.jpl.nasa.gov/naif/toolkit_MATLAB.html. MICE is a MATLAB implementation of the SPICE library created by JPL.

A Windows executable program, FORTRAN source code and PDF documentation for tlto_sos can be downloaded from the following site; https://sourceforge.net/projects/aero-trajectory-optimization/files/tlto_sos.zip/download.

A Raspberry Pi executable program, FORTRAN source code and PDF documentation for tlto_sos can be downloaded from the following site; https://sourceforge.net/projects/aero-traj-optim-gfortran-raspi/files/Finite-burn%20Translunar%20Trajectory/tlto_sos.zip/download.

PDF documentation for the tlto_sos computer program can be downloaded from https://sourceforge.net/projects/aero-trajectory-optimization/files/Computer%20Methods%20for%20Aerospace%20Trajectory%20Optimization.pdf/download