The experimental data on the surface rheological characteristics of dodecyl dimethyl phosphine oxide solutions obtained in a fully automatic oscillating bubble device Under microgravity conditions in the frequency range 0.01-100 Hz are presented. The complex Surface elasticity modulus is obtained form the amplitude and phase-frequency characteristics of established pressure oscillations in a closed cell without calibration experiments by direct calculation of the necessary coefficients. The characteristics of the adsorption layers obtained front the elasticity modulus are in good agreement with adsorption isotherms and equations of state accounting for the intrinsic (2D) monolayer compressibility. (C) 2004 Elsevier Inc. All rights reserved.