The astrodynamics calculations are all implemented as static functions in the SGP4 class/module. The ElsetRec datastructure is used to maintain initialization state across those methods. For convenience, I have implemented the TLE class. The constructor accepts the two lines of the the two-line element set as arguments. To then propagate (simulate) the orbit, I have implemented a few getRV methods in each language. One will accept the number of minutes since the epoch as an argument. In most languages, I've also implemented a version of getRV that accepts a Date or DateTime object to simulate the orbit at a specific point in time. Sometimes, if I didn't find a helper class in the target language that I liked, I simply used the number of milliseconds since January 1, 1970 as the argument.

I've delivered production code in all of these languages.

*[C](#c)

*[C++](#c-1)

*[C#](#c-2)

*[R](#r)

*[Ruby](#ruby)

I've only done my own projects in these languages.

*[Rust](#rust)

gcc -o testsgp4 SGP4.c TLE.c TestSGP4.c -lm

ruby TestSGP4.rb

Typical Errors 0.006722191115878764 mm, 0.0004812040288887651 mm/s

The Rust version was ported from the C version. To run the code go to the rust directory and type:

cargo run

Typical errors r=0.006589293163823231 mm, v=0.00048047055139244986 mm/s