TLEs can be used to calculate position and velocity in an earth centered coordinate system, from which the position and velocity at every other time in any other coordinate system can be calculated, favorably by numerical means. The limit of accuracy is given by the initial position and velocity which propably is not too good if the TLE it is based upon is only an approximation, mainly because the calculation may have some chaotic properties due to a short pass with the moon and a final orbit close to the earth-moon-system. During the Apollo missions there was measurement of at least the spacecraft trajectory between earth and moon by Doppler radar. I would suggest to look for such data first when one wants to calculate solar orbits of debris stages. I do not know if the Horizons Ephemeris System gives this data for Apollo stages. Moritz Heger, Ingolstadt, Germany ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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