  The planetary ephemerides play a crucial role for spacecraft navigation,
mission planning, reduction and analysis of the most precise astronomical
observations. The construction of such ephemerides is highly constrained by the
tracking observations, in particular range, of the space probes collected by
the tracking stations on the Earth. The present planetary ephemerides (DE,
INPOP, EPM) are mainly based on such observations. However, the data used by
the planetary ephemerides are not the direct raw tracking data, but
measurements deduced after the analysis of raw data made by the space agencies
and the access to such processed measurements remains difficult in terms of
availability.
  The first part of the study deals with the analysis of the Mars Global
Surveyor (MGS) tracking data. The tracking observations containing one-, two-,
and three-way Doppler and two-way range are then used to reconstruct MGS orbit
precisely. As a supplementary exploitation of MGS, we derived the solar corona
model and estimated the average electron density along the line of sight
separately for slow and fast wind regions. Fitting the planetary ephemerides,
including additional data which were corrected for the solar corona
perturbations, noticeably improves the extrapolation capability of the
planetary ephemerides and the estimation of the asteroid masses (Verma et al.,
2013). The second part of the thesis deals with the complete analysis of the
MESSENGER tracking data. This analysis improved the Mercury ephemeris up to two
order of magnitude compared to any latest ephemerides. Such high precision
ephemeris, INPOP13a, is then used to perform general relativity tests of
PPN-formalism. Our estimations of PPN parameters (? and ) are the most
stringent than previous results (Verma et al., 2014).
