A general Fortran code for solutions of problems in space mechanics [pdf]
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Re: A general Fortran code for solutions of problems in space mechanics [pdf]
#2From NASA, 1963, by William C. Strack, Wilbur F. Dobson, and Vearl N. Huff
As described herein, this code is designed to operate on an IBM 704 computer that has an 8000 word (8 K) memory and at least 1 K of drum.
Takes me back to when I lived and breathed such code for early geophysical and remote sensing work.
Re: A general Fortran code for solutions of problems in space mechanics [pdf]
#3Love seeing stuff like this. The corrections for an oblate spheroid threw me for a loop at first, until I realized "yeah, of course". I've only ever played around with ideal bodies when simulating the n-body problem (sounds a bit raunchy...) so never even considered the fact that a rotating planet isn't perfectly spherical.
Re: A general Fortran code for solutions of problems in space mechanics [pdf]
#4Idle question: in the days before TeX, when manuscripts like this were hammered out on Remington office typewriters, how did authors handle symbols?
In this manuscript for example you can see that power superscripts are really just regular numbers typed at an offset (perhaps rotating the paper around the platen one notch instead of the two that would be a whole line feed). But what about the vectors and the giant sigma? All hand drawn over the top of a typed manuscript?
Re: A general Fortran code for solutions of problems in space mechanics [pdf]
#5Idle question: in the days before TeX, when manuscripts like this were hammered out on Remington office typewriters, how did authors handle symbols? In this manuscript for example you can see that power superscripts are really just regular numbers typed at an offset (perhaps rotating the paper around the platen one notch instead of the two that would be a whole line feed). But what about the vectors and the giant sig…
Yes, I believe they're drawn or stenciled in. Some amount of care has been taken here to produce a more professional-looking result, but you can find plenty of old typed papers where math is obviously handwritten in. Like John Nash's thesis: https://library.princeton.edu/sites/g/files/toruqf6021/files...
Re: A general Fortran code for solutions of problems in space mechanics [pdf]
#6My first thought was to upload the PDF to Qwen3 and ask it to reimplement in Python using NumPy, Astropy, etc. Have to work on the day job, but could be some educational fun learning and Jupyter plots in my near future. Anyway, the generated code looks promising and contains the requisite green tick and bar graph emojis, so what's not to like?
Re: A general Fortran code for solutions of problems in space mechanics [pdf]
#7Idle question: in the days before TeX, when manuscripts like this were hammered out on Remington office typewriters, how did authors handle symbols? In this manuscript for example you can see that power superscripts are really just regular numbers typed at an offset (perhaps rotating the paper around the platen one notch instead of the two that would be a whole line feed). But what about the vectors and the giant sig…
> how did authors handle symbols?
Mostly they didn't .. it was handballed to the secretaries of the math and physics typing pool who used stencils, high end typewriters, and other template mechanisms.
A good many such secretaries were reasonably talented math and physics graduates themselves who had limited opportunity to be hired to do "a man's work".
Re: A general Fortran code for solutions of problems in space mechanics [pdf]
#8It looks like they chose to use the "universal gravitational constant" "k" instead of Newton^s constant, "G": p.23, "k^2 = universal gravitational constant, 1.32452139x10^20, m^3/(sec^2)(sun mass units)"
I think "k" was also known as "Gaussian gravitational constant" https://en.wikipedia.org/wiki/Gaussian_gravitational_constan...
But the value and unit of "k" given in the Wikipedia page is different. Do you know what NASA document means by "universal gravitational constant" in modern sense?
Re: A general Fortran code for solutions of problems in space mechanics [pdf]
#9Idle question: in the days before TeX, when manuscripts like this were hammered out on Remington office typewriters, how did authors handle symbols? In this manuscript for example you can see that power superscripts are really just regular numbers typed at an offset (perhaps rotating the paper around the platen one notch instead of the two that would be a whole line feed). But what about the vectors and the giant sig…
Godement in his analysis exposition briefly talks about this, it was all hand drawn.
Re: A general Fortran code for solutions of problems in space mechanics [pdf]
#10It’s amazing how many times I search for some space-related technical thing and I end up with a paper from NASA Glenn (used to be Lewis)