On force-field models of the spacecraft flyby anomaly

TL;DR

This paper investigates whether a velocity-independent force field can explain the spacecraft flyby anomaly and finds it cannot, but demonstrates that velocity-dependent quadratic fields can model the anomaly effectively.

Contribution

The study proves the impossibility of velocity-independent force fields explaining the flyby anomaly and provides examples of velocity-dependent quadratic fields that do.

Findings

Velocity-independent force fields cannot reproduce the flyby anomaly.

Quadratic velocity-dependent fields can model the flyby anomaly.

The empirical prediction formula is not consistent with velocity-independent forces.

Abstract

Recently, Anderson et al. published an empirical prediction formula for the so far unexplained parts of the velocity changes of spacecrafts during Earth flybys. In the framework of a perturbational approach, we show that there is no velocity-independent force field of the Earth - in addition to its Newtonian gravity field - that is to reproduce this formula. However, we give examples for fields modeling exactly the flyby anomaly which are quadratic functions of the velocity of the spacecraft.