MathATESAT: A Symbolic-Numeric Environment in Astrodynamics and Celestial Mechanics. The increase in the facilities of the general computer algebra system, in particular Mathematica, and hardware evolution have supplied us with the possibility of developing a new environment called MathATESAT. Our new system collects all the tools necessary to carry out high accuracy analytical theories in order to analyze the quantitative and qualitative behaviour of a dynamic system. Real applications for the calculation of several expansions of Disturbing Functions, classical expansions of the Kepler problem and some details involved in the qualitative analysis of dynamic systems, are used to illustrate the capability of MathATESAT.