Another look at the Pioneer anomaly

The unexpected frequency shift observed by the Pioneer team, usually described as an anomalous acceleration is analyzed from the perspective of two alternative assumptions on the origin of cosmological redshift (Hubble effect). One is the standard assumption of an "expanding space", the other is the assumption of an energy loss of photons without expanding space sections ("tiring light"). We find that under both assumptions the anomaly can be dissolved and turns out as a direct manifestation of the Hubble effect (Hubble law) inside the solar system. For the expanding space hypothesis new questions arise from this finding