n

The Mean Motion (n) is defined as the number of orbits the satellite completes about the Earth in exactly 24 hours (one solar day).

Theoretically, the value of the Mean Motion can be anywhere between 0 and 18 orbits per solar day.

The Period (T) of the orbit can be found by taking the Mean Motion's reciprocal (1/n). The satellite orbit's semi-major axis (a) can be found by using the following equation:

a³ = GM / (2pn)²

where a = the Semi-Major Axis of the satellite's orbit;
          G = the Gravitational Constant;
          M = the Mass of the Earth; and
          n = the Mean Motion of the satellite's orbit.

The cube of the semi-major axis is directly proportional to the square of the mean motion's reciprocal (period). This is Kepler's Third Law of Orbital Motion.