I am doing trajectory optimization, and want to use NASA's Evolutionary Mission Trajectory Generator (EMTG) software to investigate dates for various trajectories. However, this software does not come ready to use "out of the box", and seems to involve a complicated installation procedure. NASA has some links on their website that lead to a now non-existent SourceForge page, where I assume I would have found relevant documents, and there seems to be very little info on how to use this software online. I have found two versions of EMTG: one from a github page, which appears to be the software in a raw form, it has to be compiled/built before it can be used, and what appears to be a more ready to use version here.

However, in either case, I am not sure how to proceed. I know that using this software involves Visual Studio somehow, and the SNOPT optimizer has to be added to it. I have an academic license for SNOPT, and access to all of its variations, Matlab and Fortran, but it doesn't appear to be a simple case of "dragging and dropping" SNOPT's files to a specific folder. This is not helped by the fact that there are 4 variations of the Fortran version of SNOPT to download on their website.

Therefore, assuming I'm a complete beginner when it comes to doing anything with software except running them as is (so no knowledge about using Visual Studio to run them, compiling them, using solution files, cmake etc.) which version of EMTG do I download, and how do I set it up so I can use it?

  • $\begingroup$ This appears to be a bad news / good news / more bad news kind of thing. The bad news is that SourceForge links in the NASA open source page on EMTG is broken. That project no longer exists at SourceForge. The good news is, that as you have found, the software has been moved to github.com/nasa. I don't understand why anyone is using SourceForge nowadays. It was an ad-filled, virus-injecting site seven years ago. Supposedly the new owners have fixed the latter issue, but it remains chock-full of ads. (continued) $\endgroup$ Jun 11, 2022 at 12:49
  • $\begingroup$ The good news: The repo appears to have been transferred from SourceForge to GitHub, as you have found. A word of admonishment to you: Learn how to build software. Downloading binaries, unless the binaries are from a very reputable site, is a way to turn your computer into a brick or into an outlet for blackhats to exploit. More good news: Github is a very reliable site, and the maintainers of a repo can install binaries. (continued) $\endgroup$ Jun 11, 2022 at 12:57
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    $\begingroup$ Back to the bad news category, the maintainers of EMTG (if there are any) have not created a releases subdirectory. More bad news: The repo looks bad. There is no documentation, it hasn't been updated for 17 months, and it is sloppy. For example, they call the NASA open source agreement "NOSA EMTG Version 9.pdf". There's a concept called "coffee stains on the flip down trays." To some people, those stains mean that the airline is not properly maintaining their engines. Calling NASA "NOSA" is, to me, a huge strain on the flip-down tray. That was jarring. More sloppiness exists throughout. $\endgroup$ Jun 11, 2022 at 13:10
  • $\begingroup$ @David Hammen Thanks for the info, I've also noticed that NASA doesn't seem to take good care of their online resources, there's a lot dead links on their websites. GMAT's online presence is especially a disorganized mess. I hear you on the building software part, I've come to realize in the past months that it's necessary when it comes to using specialized software. Do you know what the difference between the EMTG they have on Github and the one linked in the GSFC Open Source Software website is? $\endgroup$
    – kardalos
    Jun 11, 2022 at 13:35
  • $\begingroup$ Some NASA open source is well-maintained, well-documented, and well-tested. Other NASA open source is not. EMTG appears to fall in the latter category. And no, I do not know the difference between EMTG on SourceForge vs that on GItHub for two reasons. One is because the SoureForge version appears to be gone. The other is that I'm not an EMTG user. (If I was I might be able to answer your question.) Perhaps another of the members of this site has used EMTG and can answer you question. $\endgroup$ Jun 11, 2022 at 22:49


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