Mean orbital distances r_n of planets from the Sun and of major satellites from the parent planets Jupiter, Saturn and Uranus are described by the square law r_n = r_1n^2, where the values of n are consecutive integers, and r_1 is the mean orbital distance expected at n = 1 for a particular system. Terrestrial planets and Jovian planets are analysed as separate systems. Thus, five independent solar-like systems are considered. The basic assumption is that specific orbital angular momentum is "quantized". Consequently, all orbital parameters are also discrete. The number n relates to the law of orbital spacing. An additional discretization, related to r_1, i.e. to the scale of orbits, accounts for the detailed structure of planar gravitational systems. Consequently, it is also found that orbital velocity v_n multiplied by n is equal to the multiple of a fundamental velocity v_0 almost equal to 24 km s^-1 , valid for all subsystems in the Solar System. This velocity is equal to one of the "velocity" increments of quantized redshifts of galaxies
