An apparatus is disclosed that is a self-contained gas management system (hereinafter “GMS”) that accommodates individual canisters of highly energetic small munitions, but is not so limited. By decoupling the gas management system for a given munition from an adjacent munition, the risk of downing a multi-pack launcher or munition adapter is reduced. Thermal wear, overheating, restrained firing and aft closure debris can be isolated through the separation of gas management systems. In addition, the GMS allows for ease of replenishment and maintenance of a given sub-cell of a multi-pack system. The GMS works with existing munitions and canisters without the need to modify them. Each GMS is dimensioned to fit the canistered munition it receives as well as the launch system with which it is used. The illustrative GMS comprises a plenum, and a first and a second uptake structure. The plenum receives the exhaust from the canistered munition when the munition fires. The plenum is fluidically coupled to the first and second uptake structures. The uptake structures in the illustrative embodiment receive the missile exhaust from the plenum and vent the exhaust to the atmosphere. In the illustrative embodiment, the first and second uptake structures are disposed along opposite sides of the canistered munition, flanking it.