  All anomalous velocity increases until now observed during the Earth flybys
of the spacecrafts Galileo, NEAR, Rosetta, Cassini and Messenger have been
correctly calculated by computer simulation using an asymmetric field term in
addition to the Newtonian gravitational field. The specific characteristic of
this term is the lack of coupling to the rotation of the Earth or to the
direction of other gravitational sources such as the Sun or Moon. Instead, the
asymmetry is oriented in the direction of the Earth's motion within an assumed
unique reference frame. With this assumption, the simulation results of the
Earth flybys Galileo1, NEAR, Rosetta1 and Cassini hit the observed nominal
values, while for the flybys Galileo2 and Messenger, which for different
reasons are measured with uncertain anomaly values, the simulated anomalies are
within plausible ranges. Furthermore, the shape of the simulated anomaly curve
is in qualitative agreement with the measured Doppler residuals immediately
following the perigee of the first Earth flyby of Galileo. Based on the
simulation, an estimation is made for possible anomalies of the recently
carried out flybys of Rosetta at Mars on 25.02.07 and at the Earth on 13.11.07,
and for the forthcoming Earth flyby on 13.11.09. It is discussed, why a so
modelled gravitational field has not been discovered until now by analysis of
the orbits of Earth satellites, and what consequences are to be considered with
respect to General Relativity.
