Measurements taken by the solar wind experiments aboard the ISEE 2 satellite show evidence for H+ ions, originating from neutral hydrogen moving with a speed much lower than that of the solar wind. Positive ion fluxes are measured as a function of energy and flow direction and accumulated over a time of few hours, in which the solar wind and magnetic field parameters remain approximately constant. A model given by Vasyliunas and Siscoe (1976) is used to predict the expected location of these ions in velocity space. A consistent correlation is found between predictions and measurements in three periods of time: order of magnitude estimates of the ion flux range between 104 and 105 cm-2 s-1. In the region surrounding the Earth, the neutral hydrogen consisting primarily of interstellar and geocoronal gas. The present preliminary results presented do not allow to evaluate the relative contributions of the two populations to the observed fluxes.