Pole and prime meridian expressions for Phobos and Deimos

Simple trigonometric expressions are derived for the right ascensions and declinations of the spin axes of Phobos and Deimos as well as for their prime meridians. Simple expressions are possible since both satellites are in synchronous rotation about Mars and since the orbits of both satellites are accurately modeled as precessing ellipses. Spin axis expressions reflect the offset and precession of the orbit pole about the Laplacian pole. Prime meridian expressions include orbital mean motion, long-period solar perturbations, secular acceleration, and short-period, tidally induced forced libration. These simple expressions agree with rigorous expressions to + or - 0.2 deg.