Aspects of the disclosure relate to flight termination systems for tethered aerial vehicles having envelopes. For instance, a flight termination system may include a wire heating element arranged in a loop around the balloon envelope and connected to a strain relief connector, the strain relief connector, and an electrical cable connected to the strain relief connector. The electrical cable is configured to provide current to the wire in order to melt envelope material of the envelope and terminate a flight of the aerial vehicle.

A high-altitude balloon manufacturing apparatus. The apparatus includes one or more extruders and one or more extrusion dies in fluid communication with the extruders. Each extrusion die is shaped to define one or more connector channels and one or more layering channels. The connector channels define extrudate flow paths between the layering channels.

A high-altitude balloon manufacturing apparatus. The apparatus includes one or more extruders and one or more extrusion dies in fluid communication with the extruders. Each extrusion die is shaped to define one or more connector channels and one or more layering channels. The connector channels define extrudate flow paths between the layering channels.

A method of fabricating a high-altitude balloon. The method includes coextruding at least two adjacent continuous layers of extrudate, extrusion-bonding the layers of extrudate to one another along an edge of the sheets of extrudate to form a seam, and cooling the extrudate.

A method of fabricating a high-altitude balloon. The method includes coextruding at least two adjacent continuous layers of extrudate, extrusion-bonding the layers of extrudate to one another along an edge of the sheets of extrudate to form a seam, and cooling the extrudate.

A high altitude balloon. A plurality of layers of coextruded extrudate are formed in a seamless sheet in a shape that defines a balloon envelope. Delaminator layers may be interposed between two or more of the layers of extrudate.

A high altitude balloon. A plurality of layers of coextruded extrudate are formed in a seamless sheet in a shape that defines a balloon envelope. Delaminator layers may be interposed between two or more of the layers of extrudate.

Co-extruded and extruded high-altitude balloons and apparatus and methods for manufacture. A high-altitude balloon has a plurality of layers of coextruded balloon panel extrudate, a first one of the layers extrusion-bonded to a second one of the layers along a first edge, the second one of the layers extrusion-bonded to a third one of the layers along a strip spaced apart from the first edge, extrusion-bonding of successive layers alternating between the first edge and the strip, the first one of the layers and the last one of the layers extrusion-bonded together along a second edge.

Co-extruded and extruded high-altitude balloons and apparatus and methods for manufacture. A high-altitude balloon has a plurality of layers of coextruded balloon panel extrudate, a first one of the layers extrusion-bonded to a second one of the layers along a first edge, the second one of the layers extrusion-bonded to a third one of the layers along a strip spaced apart from the first edge, extrusion-bonding of successive layers alternating between the first edge and the strip, the first one of the layers and the last one of the layers extrusion-bonded together along a second edge.

The invention concerns a device for seeding a cloud cell, comprising means for conveying an active substance and means for delivering said active substance. In order to comply with standard and safety requirements, said device comprises aerostatic means that cooperate with the means for conveying said active substance. The invention further concerns a system for seeding a cloud cell, comprising a seeding device according to the invention and a remote electronic entity capable of communicating with said device via communication means over a wired or wireless link.