The effect of linearly chirped pulses in condensed phase ultrafast pump-probe experiments is investigated by classical simulations for the model system of I-2 isolated in a Kr matrix. The central frequency of the probe laser is selected to monitor exclusively the event of first collision and recoil of atoms from the host cage. It is shown that a chirped probe pulse enables characterization of the magnitude and sign of the momentum of the evolving trajectory flux. This can be understood by transforming the frequency-time profile of the probe pulse to coordinate-time space, and noting that the observable signal is a function of the relative group velocities of the traveling wave packet and the traveling window function. The effect of the pump pulse chirp, is a measure of the controllability of the evolving dynamics. In the particular case studied, breaking and remaking of the I-2 bond near the dissociation limit of the bare molecule, it is shown that the memory of the system outlasts the collision with the cage. Negatively chirped pulses produce a more tightly focused wave packet during recoil, leading to a stronger population coherence in the subsequent dynamics.