Has anyone coded up any type of earth orbit satellite propagators in Mathematica? (i.e. two-body, analytic J2, Cowell method, semi-analytic?) Apparently Wolfram Research is working on a module called Astronomica, but the sales rep couldn't give me a release date, specs. etc. I have a need to generate ephemeris for a series of polar orbit satellites, and don't want to "reinvent the wheel" if someone has already gone down that path before.