-A simple physical model for calculation of the ioninduced soft error rate in space environment has been proposed, based on the phenomenological cross section notion. Proposed numerical procedure is adapted to the multiple cell upset characterization in highly scaled memories. Nonlocality of the ion impact has been revealed as the key concept determining the difference between physical processes in low scaled and highly scaled memories. The model has been validated by comparison between the simulation results and the literature on-board data. It was shown that proposed method provides single-valued prediction results correlating well with on-board data based solely on cross section data and LET spectra without any hidden fitting parameters and procedures.