The medium response of solid hydrogens to an impulsive perturbation has been studied using Rydberg excitation of an NO impurity. This leads to formation of an "electronic" bubble which corresponds to a cage radius increment of about 25%. The process has been followed in real-time using femtosecond pump-probe spectroscopy. Bubble dynamics is characterized by a one-way expansion of the cage with no recurrencies of the cage boundaries in both solid H2 and D2. The data is interpreted in terms of a dominant energy disspation by emission of sound waves and friction. [on SciFinder (R)]