// ORBITAL LOGISTICS AND PROPULSION TERM
Mean Anomaly
A measure of how far along a satellite is in its orbit, assuming it moves at a constant speed in a perfect circle, even though real orbits are usually elliptical. It helps predict a satellite's position at a given time.
TECHNICAL DEFINITION
Mean Anomaly (M) is an angular orbital element representing the fraction of an orbital period that has elapsed since the pericenter passage, assuming a circular orbit with constant angular speed, crucial for predicting spacecraft position in two-body problem solutions.
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
- M
- orbital position angle
- average angular position
USAGE NOTE
Used in ephemeris calculations to determine a satellite's position over time.
DEVELOPERS
Organizations developing technology related to Mean Anomaly.
As a leading center for robotic space exploration, JPL designs complex interplanetary trajectories and navigates spacecraft. This requires extremely precise calculations of orbital elements, including mean anomaly, to ensure missions reach celestial targets like Mars and beyond.
ESA designs, launches, and operates a wide range of satellites. Its European Space Operations Centre (ESOC) is responsible for controlling spacecraft in orbit, which involves constant orbit determination, prediction, and adjustments based on orbital parameters like mean anomaly.
Developer of Systems Tool Kit (STK), a physics-based software platform used extensively for modeling and analyzing space missions. The software's core function is to propagate orbits using classical orbital elements, including mean anomaly, to predict an object's position.
Provides commercial space situational awareness (SSA) and collision avoidance services by mapping Low Earth Orbit with ground-based radars. Their platform constantly determines and refines orbital parameters for satellites and debris to predict their future positions.
Operates the Starlink mega-constellation, requiring sophisticated systems for space traffic management and collision avoidance. This relies on continuous, precise tracking and prediction of each satellite's orbit using Keplerian elements.
A federally funded research and development center (FFRDC) that provides technical and scientific guidance for national security space programs. Their astrodynamics experts develop advanced techniques and software for high-precision orbit determination and prediction.
Specializes in space situational awareness (SSA) by operating a global network of optical telescopes to track and characterize space objects. Their work involves the precise determination of orbital states, including mean anomaly, for thousands of resident space objects.
Operates the world's largest constellation of Earth observation satellites. The company's mission operations team must accurately model and predict the orbits of hundreds of spacecraft to ensure proper imaging coverage and constellation health.