Quasi constant-time orbit propagation without solving Kepler's equation

Efficient methods for solving Kepler's equation, a transcendental equation relating orbital position as a function of time, have been studied for centuries and generated a vast literature. This paper proposes a shift in focus from the efficient solution of Kepler's equation to the alternative that, when the position of the spacecraft at precise instants in time is not required, one may simply use a quasi constant-time propagation technique to obtain the spacecraft trajectory. This method is much faster than solving Kepler's equation iteratively and provides, during the initial stages of mission analysis, a good solution from which deeper investigation of the orbit characteristics can proceed.

Quasi constant-time orbit propagation without solving Kepler's equation Conference Paper