H$_2$O masers associated with the massive star formation region W49N were observed in frames of the Space-VLBI project RadioAstron. Ultra-compact structures in the masers were detected on space-ground baselines up to 9.6 Earth diameters. The flux density of ultra-compact features does not exceed a percent of the single dish flux density. Some results of the data processing for three observing sessions performed in 2014-2015 are presented. The lower limit of minimal brightness temperatures and estimates of angular sizes of the brightest features corresponding to the ultra-compact maser spots of the W49N complex are obtained.