Recent investigations in holographic mass memory systems have produced proof of concept demonstrations that have highlighted their potential for providing unprecedented capacity, data transfer rates and fast random access performance [1–4]. The exploratory nature of most such investigations has been largely confined to benchtop experiments in which the practical constraints of packaging and environmental concerns have been ignored. We have embarked on an effort to demonstrate the holographic mass memory concept by developing a compact prototype system geared for avionics and similar applications, which demand the following features (mostly interdependent factors): (1) solid-state design (no moving parts), (2) fast data-seek time, (3) robustness with respect to environmental factors (temperature, vibration, shock). In this chapter, we report on the development and demonstration of two systems, one with 100 Mbytes and the other with more than 1 Gbyte of storage capacity. Both systems feature solid-state design with the addressing mechanism realized with acousto-optic deflectors that are capable of better than 50 µs data seek time. Since the basic designs for the two systems are similar, we describe only the larger system in detail. The operation of the smaller system has been demonstrated in various environments, including hand-held operation and thermal/mechanical shock, and a photograph of the smaller system is provided as well as actual digital data retrieved from the same system.