A mitigation control system, for performing an active hazard mitigation method, is arranged in an environment containing an energetic material and includes an abnormal temperature sensor for detecting an abnormal temperature of the environment, a power source that is mechanically actuated by the abnormal temperature sensor when the abnormal temperature exceeds a predetermined abnormal temperature threshold, a mitigation controller that is actuated by the power source, and a plurality of local temperature sensors that are communicatively coupled to the mitigation controller and are arranged for detecting critical temperatures in specific regions of the environment. The mitigation controller executes a mitigation action when one of the critical temperatures exceeds a predetermined critical temperature threshold for the corresponding specific region.

A thermal protection system is provided for a vehicle substructure. The thermal protection system comprises an outer layer for protecting the vehicle substructure. The thermal protection system further comprises an inner layer for conforming to the vehicle substructure. The thermal protection system also comprises an insulation layer sandwiched between the inner and outer layers. The insulation layer includes a porous low-density ceramic insulating material having a densified portion that covers an inner surface of the outer layer to strengthen adhesion.

A method includes obtaining thermal energy from a structure to be cooled, where the structure includes micro-channels. The method also includes providing the thermal energy to a water-based polymer network, where the water-based polymer network includes a gel formed using a polymer and water. The method further includes generating one or more gases by heating the water-based polymer network, where generating the one or more gases includes releasing the water in the water-based polymer network to produce steam. In addition, the method includes passing the one or more gases through the micro-channels to remove at least some of the thermal energy from the structure.

A system includes a guided munition having a housing. A first reservoir is defined within the housing holding a first chemical reactant. A second reservoir is defined within the housing, wherein the second reservoir holds a second chemical reactant configured to undergo an endothermic reaction with the first chemical reactant. A frangible barrier separates between the first and second reservoirs. The frangible barrier is configured to break under forces acting on the guided munition as the guided munition is fired from a weapon. An electronic device can be housed within the housing in thermal contact with at least one of the first reservoir and/or second reservoir for cooling the electronic device with an endothermic reaction upon mixing of the first and second chemical reactants.

A system includes a guided munition having a housing. A first reservoir is defined within the housing holding a first chemical reactant. A second reservoir is defined within the housing, wherein the second reservoir holds a second chemical reactant configured to undergo an endothermic reaction with the first chemical reactant. A frangible barrier separates between the first and second reservoirs. The frangible barrier is configured to break under forces acting on the guided munition as the guided munition is fired from a weapon. An electronic device can be housed within the housing in thermal contact with at least one of the first reservoir and/or second reservoir for cooling the electronic device with an endothermic reaction upon mixing of the first and second chemical reactants.

A wedge-based heat switch includes a plurality of wedge segments on a shaft, an energy storage element (e.g., a spring or pressurized cavity) configured to store (and release) energy via compression or expansion of the element along the shaft and a temperature activated phase transition material. A temperature stimulus activates the phase transition material to release the stored energy and move the wedge segments axially along the shaft to expand or contract the plurality of wedge segments. The wedge-based heat switch may be configured as a unidirectional switch, either conductive-to-insulating or insulating-to-conductive, or a bi-directional switch. The specific design of the wedge-based heat switch is informed by such factors as unidirectional or bi-directional, required preloading of a surface, conductance ratio between conducting and insulating states, temperature stimulus, switching speed and form factor.

A wedge-based heat switch includes a plurality of wedge segments on a shaft, an energy storage element (e.g., a spring or pressurized cavity) configured to store (and release) energy via compression or expansion of the element along the shaft and a temperature activated phase transition material. A temperature stimulus activates the phase transition material to release the stored energy and move the wedge segments axially along the shaft to expand or contract the plurality of wedge segments. The wedge-based heat switch may be configured as a unidirectional switch, either conductive-to-insulating or insulating-to-conductive, or a bi-directional switch. The specific design of the wedge-based heat switch is informed by such factors as unidirectional or bi-directional, required preloading of a surface, conductance ratio between conducting and insulating states, temperature stimulus, switching speed and form factor.

A radar-absorbing material projectile system including a projectile with an outer layer of radar-absorbing material (RAM). A carrier or armature is disposed around the projectile, protecting the layer of RAM during the firing sequence. In some embodiments the carrier is a discarding carrier which falls away after firing, rendering the projectile low-observable with regard to radar detection due to the layer of RAM.

A system includes a flight vehicle and one or more deployable radiators. Each deployable radiator includes a structure configured to receive thermal energy and to reject the thermal energy into an external environment. The structure includes (i) multiple inline and interconnected thermomechanical regions and (ii) one or more thermal energy transfer devices embedded in at least some of the thermomechanical regions. The one or more thermal energy transfer devices are configured to transfer the thermal energy between different ones of the thermomechanical regions. At least one of the thermomechanical regions includes one or more shape-memory materials configured to cause a shape of the structure to change. The thermomechanical regions may include one or more heat input regions configured to receive the thermal energy, one or more heat rejection regions configured to reject the thermal energy into the external environment, and one or more morphable regions including the one or more shape-memory materials and configured to change shape.

A system includes a flight vehicle and one or more deployable radiators. Each deployable radiator includes a structure configured to receive thermal energy and to reject the thermal energy into an external environment. The structure includes (i) multiple inline and interconnected thermomechanical regions and (ii) one or more thermal energy transfer devices embedded in at least some of the thermomechanical regions. The one or more thermal energy transfer devices are configured to transfer the thermal energy between different ones of the thermomechanical regions. At least one of the thermomechanical regions includes one or more shape-memory materials configured to cause a shape of the structure to change. The thermomechanical regions may include one or more heat input regions configured to receive the thermal energy, one or more heat rejection regions configured to reject the thermal energy into the external environment, and one or more morphable regions including the one or more shape-memory materials and configured to change shape.