Context :

Aims : The phase scintillation of the European Space Agency ’ s ( ESA ) Venus Express ( VEX ) spacecraft telemetry signal was observed at X-band ( \lambda = 3.6 cm ) with a number of radio telescopes of the European VLBI Network ( EVN ) in the period 2009 – 2013 .

Methods : We found a phase fluctuation spectrum along the Venus orbit with a nearly constant spectral index of -2.42 \pm 0.25 over the full range of solar elongation angles from 0 ^ { \circ } to 45 ^ { \circ } , which is consistent with Kolmogorov turbulence .
Radio astronomical observations of spacecraft signals within the solar system give a unique opportunity to study the temporal behaviour of the signal ’ s phase fluctuations caused by its propagation through the interplanetary plasma and the Earth ’ s ionosphere .
This gives complementary data to the classical interplanetary scintillation ( IPS ) study based on observations of the flux variability of distant natural radio sources .

Results : We present here our technique and the results on IPS .
We compare these with the total electron content ( TEC ) for the line of sight through the solar wind .
Finally , we evaluate the applicability of the presented technique to phase-referencing Very Long Baseline Interferometry ( VLBI ) and Doppler observations of currently operational and prospective space missions .

Conclusions :