An ephemeris program generator is designed to automatically construct compact efficient ephemeris programs tailored specifically for tasks encountered in online real-time computing environments. For portability the ephemeris programs are written in standard FORTRAN IV. The analytic theory underlying the ephemeris program is the theory developed by Alfriend and Coffey which solves the zonal satellite problem is closed form. The flexibility required by a diverse user community is built into a meta-program which automatically constructs the ephemeris programs according to a program template/The program template is dictated from a terminal according to the specifications of the particular application. Using the program template the meta-program transcribes the series representing the theory into FORTRAN-compilable code. The largest version of the current ephemeris program can be held in the memory of current microcomputers and could be adapted for use in multiprocessing or distributed processing environments.