Abstract: According to one aspect, a system for midair deployment of payload may include an aerostat including an inflatable structure, at least one tether, and a trigger, the at least one tether extending between the inflatable structure and the trigger, and at least one unmanned aerial vehicle (UAV) including wings, the at least one tether mechanically coupling the at least one UAV to the inflatable structure, and the trigger actuatable to release mechanical coupling of the at least one tether between the at least one UAV and the inflatable structure in midair.

Abstract: A system for controlling contamination in hydrogen production from water-reactive aluminum includes at least one reaction vessel. For example, each reaction vessel may include a container, a conduit, and a plurality of baffles. The container may define a volume, and the conduit may define an orifice outside of the container and spaced away from the container. The plurality of baffles may be disposed in the volume to form a tortuous flow path through the volume to the orifice of the conduit to facilitate rapid production of a large quantity of hydrogen from water-reactive aluminum while reducing the likelihood that ejecta, aerosols, or a combination thereof, may escape the reaction vessel to interfere with end-use of the hydrogen produced.

Abstract: A method of packaging water-reactive aluminum may include directing at least one discrete object into a container, the at least one discrete object including an aluminum alloy, the aluminum alloy plastically deformed and non-recrystallized, introducing, into the container, a liquid metal alloy including one or more activation metals, enclosing the at least one discrete object and the liquid metal alloy with one another in the container to form a kit, for a predetermined period, exposing the kit to a heating environment, and agitating the at least one discrete object and the liquid metal alloy in the container in the heating environment during the predetermined period to form the kit into a packaged unit of water-reactive aluminum.

Abstract: A system for deploying an inflatable structure may include a balloon defining an envelope having a first stiffness, a valve assembly including a control valve, and a reactor defining a chamber having a second stiffness, the valve assembly disposed in fluid communication between the chamber and the envelope, the control valve selectively actuatable to control fluid communication between the chamber and the envelope, the second stiffness of the chamber greater than the first stiffness of the envelope, and the reactor foldable onto itself along the chamber and elastically deformable to unfold in response to an increase in pressure in the chamber.

Abstract: Aluminum can be used as a fuel source when reacted with water if its native surrounding oxide coating is penetrated with a gallium-based eutectic. When discrete aluminum objects are treated in a heated bath of eutectic, the eutectic penetrates the oxide coating. After the aluminum objects are treated, the aluminum objects can be reacted in a reactor to produce hydrogen which can, for example, react with oxygen in a fuel cell to produce electricity, for use in a variety of applications.

Abstract: Aluminum can be used as a fuel source when reacted with water if its native surrounding oxide coating is penetrated with a gallium-based eutectic. When discrete aluminum objects are treated in a heated bath of eutectic, the eutectic penetrates the oxide coating. After the aluminum objects are treated, the aluminum objects can be reacted in a reactor to produce hydrogen which can, for example, react with oxygen in a fuel cell to produce electricity, for use in a variety of applications.