A self-consistent nonlocal hydrodynamic approach was used to develop a self-consistent model of the high-rate deformation of a condensed medium in a mode transient between the elastic and hydrodynamic limits, a process accompanied by the synergetic formation of new structures and by the establishment of an informatics control closed loop between the dynamics of the internal structure of the medium and its macroscopic response. The structures formed in the transient mode can be classified as belonging to the mesoscale level (intermediate between the micro- and macroscopic levels), for which continuum mechanics is inapplicable. For the problem of propagation of a wave initiated by a high-speed impact on a solid target, an approximate semianalytical solution capable of describing the wave front transformation associated with the evolution of the internal structure was obtained. © 2008 Pleiades Publishing, Ltd.