On the Indication from Pioneer 10/11 Data of an Anomalous Acceleration
  Hubble's law, which states a linear increase in velocities with distances, can physically be understood in terms of an acceleration cH. This work proposes a connection between this "universal" acceleration seen in the solar system and the anomalous acceleration acting on the Pioneer 10/11 spacecraft, in which the Hubble constant inferred from Pioneer 10/11 data is ~ 87 km/s/Mpc. Its physical implication is discussed in relation with Mach's principle. 
Y.G. Yi