nrlmsis2

[ssmichael1]

Incorporate updated NRLMSIS2 atmospheric density model

Note: not sure how to do this yet; source code is in Fortran

[parker-research]

For anyone looking, link the v2.1 is here (with the code linked on the "Model Website" link): https://ccmc.gsfc.nasa.gov/models/NRLMSIS~2.1

Was hoping it would be straight-forward, but it looks pretty intense. Seems like the sort of conversion that a Large Language Model would do well though.

There's a few big test case files in that Fortran codebase too.