halo

Description

Halo orbit solver with modern Fortran

This application can be used to generate long-duration Earth-Moon halo orbits in the ephemeris model. A work in progress.

Build

The application is built using the Fortran Package Manager (FPM). FPM will download all the required dependencies and compile the program, and can also be used to run the tests.

fpm build --profile release

To run an example:

fpm run halo_solver --profile release -- examples/example.json

OpenMP can also be employed to speed up the process. Another example, using the Intel Fortran Compiler with OpenMP:

fpm run halo_solver --profile release --compiler ifort --flag "-qopenmp" -- examples/example.json

Or with Gfortran:

fpm run halo_solver --profile release --flag "-fopenmp" -- examples/example.json

Using qr_mumps

The qr_mumps solver can also be used, which will run much faster than the default LAPACK solver for very large problems. For this, the code must be compiled with the WITH_QRMUMPS preprocessor directive. See the build.sh and run.sh scripts for details.

Building On Windows

Work in progress....

Example:

"<intel install dir>\windows\bin\ifortvars.bat" intel64
"<intel install dir>\windows\mkl\bin\mklvars.bat" intel64

set OMP_NUM_THREADS=12

fpm run halo_solver --profile release --compiler ifort --flag "/fpp /Qmkl:parallel /Qopenmp" -- examples/example.json

Result is:

LINK : fatal error LNK1181: cannot open input file 'lapack.lib'

It's because fmin and nlsolver-fortran both have explicit lapack and blas dependencies specified in their fpm.toml files (link = ["lapack", "blas"]). If i delete those it compiles.

Other notes

Another source of CR3BP halos that can be used as initial guesses for this tool can be found here: https://ssd.jpl.nasa.gov/tools/periodic_orbits.html

Documentation

The latest API documentation can be found here. This was generated from the source code using FORD.

See also

• J. Williams, Near Rectilinear Halo Orbits, July 31, 2022 [degenerateconic.com]
• qr_mumps -- a software package for the solution of sparse, linear systems on multicore computers.

Reference

• J. Williams, D. E. Lee, R. J. Whitley, K. A. Bokelmann, D. C. Davis, C. F. Berry, "Targeting Cislunar Near Rectilinear Halo Orbits for Human Space Exploration", 27th AAS/AIAA Space Flight Mechanics Meeting, Feb. 2017
• J. Williams, R. D. Falck, and I. B. Beekman, "Application of Modern Fortran to Spacecraft Trajectory Design and Optimization", 2018 Space Flight Mechanics Meeting, 8–12 January 2018, AIAA 2018-145.
• E. M. Z. Spreen, "Trajectory Design and Targeting For Applications to the Exploration Program in Cislunar Space", PhD Dissertation, Purdue University School of Aeronautics and Astronautics, May 2021