# Why is FORTRAN recommended for astrodynamics rather than MATLAB?

I understand that FORTRAN might be faster in terms of computation time, but I don't understand why it is always recommended by people in the field. Everyone tends to avoid MATLAB for astrodynamics; is there a solid reason behind this, or is it just the preference of the majority?

MATLAB offers a lot of features not found in FORTRAN (such as visualizations or linking with other software).

• Can you give some examples of these recommendations? – Organic Marble Dec 30 '19 at 19:23
• Isn’t the recommendation “use a validated code”, many of which happen to be written in FORTRAN because they’re old and experienced? – Bob Jacobsen Dec 30 '19 at 21:14
• @uhoh ah this makes sense, basically FORTRAN is used because its a lower level of programming. I am currently "literally right now" writing some code for orbital analysis and I decided to write the libraries both in MATLAB and FORTRAN since I am still convinced with MATLAB but the astrodynamic society does FORTRAN only :) – John Dec 30 '19 at 21:40
• This comment thread makes me happy since my simulation engineering years were using FORTRAN. I chuckled at the 'lower level' comment, remembering assembly language routines! – Organic Marble Dec 30 '19 at 22:31
• I can't answer specifically on FORTRAN except for the use of legacy code (which is already mentioned in the comments) but I personally use C for my astrodynamics applications. Numerical integration is a pretty intensive task and C or FORTRAN are much better at performing it quickly than MatLab. I've previously linked an atmospheric model (JB2008) written in FORTRAN to my propagator in C because there was no implementation of it in C already. Write your core in FORTRAN or C and use MEX to call it from MatLab and process your results there. Nobody wants to plot anything from FORTRAN or C. – Alexander Vandenberghe Dec 31 '19 at 14:16

• +1 for an authoritative answer by someone who propagates orbits in Julia! – uhoh Jan 2 at 3:03