// ORBITAL LOGISTICS AND PROPULSION TERM
Mean Motion
The average angular speed of a satellite as it travels around its orbit, indicating how quickly it completes one full revolution.
TECHNICAL DEFINITION
Mean Motion (n) is the average angular speed required for a body to complete one revolution in an orbit, derived from the orbital period and semi-major axis, fundamental for calculating orbital position and period.
BACKGROUND
Outer space, or simply space, is the expanse that exists beyond Earth's atmosphere and between celestial bodies. It contains ultra-low levels of particle densities, constituting a near-perfect vacuum of predominantly hydrogen and helium plasma, permeated by electromagnetic radiation, cosmic rays, neutrinos, magnetic fields and dust. The baseline temperature of outer space, as set by the background radiation from the Big Bang, is 2.7 kelvins.
READ MORE ON WIKIPEDIASYNONYMS & ALIASES
- Average angular velocity
- orbital frequency
- orbital rate
USAGE NOTE
Directly related to the orbital period and used in calculating a satellite's position.
DEVELOPERS
Organizations developing technology related to Mean Motion.
Develops the Systems Tool Kit (STK), a physics-based software platform for modeling and analyzing assets in space. Mean motion is a fundamental parameter used in its astrodynamics engine for orbit propagation, satellite analysis, and mission planning.
Operates a global network of phased-array radars to provide high-resolution tracking of satellites and debris in Low Earth Orbit (LEO). Their space situational awareness and collision avoidance services are based on precise orbit determination, which uses mean motion as a key descriptor.
The 18 SDS maintains the U.S. Department of Defense's catalog of space objects and provides foundational space situational awareness. They generate and distribute Two-Line Element (TLE) sets, a standard data format for orbital information where mean motion is a critical field.
Specializes in Space Domain Awareness (SDA) by operating the world's largest commercial network of optical telescopes to track objects, primarily in geosynchronous (GEO) orbit. Their services depend on the constant calculation and refinement of orbital parameters, including mean motion.
Develops autonomous collision avoidance and space traffic management software for satellite operators. Their platform ingests orbital data and runs high-fidelity orbit propagations, which are based on mean motion and other elements, to predict conjunctions and recommend maneuvers.
As a leading center for robotic space exploration, JPL is a world leader in astrodynamics and deep space navigation. They develop and use highly precise trajectory models and tools, like the SPICE toolkit, where mean motion is a foundational concept for predicting spacecraft positions.
This office coordinates ESA's activities related to space debris, including providing operational collision avoidance services for ESA missions. Their work is fundamentally based on orbital mechanics and the propagation of object states using parameters like mean motion to predict future positions.
Provides a space situational awareness and data analytics platform that fuses data from disparate sources to create a comprehensive operational picture. The platform's capabilities for satellite tracking and conjunction analysis rely on orbital propagation models that use mean motion.