Abstract: Hinge pins for foldable aircraft wings are described. An example apparatus includes a hinge pin to rotatably couple a foldable tip of an aircraft wing to a fixed structure of the aircraft wing. The hinge pin includes a first flange, a second flange spaced apart from the first flange along a central axis of the hinge pin, and a through hole oriented along the central axis.

Abstract: One embodiment is a system comprising fuel tank comprising a pressure vessel for storing fuel for a vehicle, the fuel tank disposed within a fuselage of the vehicle and extending a majority of a length of the fuselage, wherein a center of gravity of the fuel tank is substantially aligned with a center of gravity of the fuselage. The fuel tank may be disposed within the fuselage such that the fuel tank bears at least a portion of a load borne by the fuselage. Alternatively, the fuel tank may be disposed within the fuselage such that the fuel tank is isolated from loads borne by the fuselage. In certain embodiments, the fuel tank comprises a filament wound pressure vessel.

Abstract: The technology relates to a telescoping support structure which can be suspended between two objects. The telescoping support structure uses projections between adjacent tubular sections in order to prevent the adjacent tubular sections from falling away from one another. Although the telescoping support structure may be utilized in various different environments and circumstances, it may be of particular usefulness in the field of high-altitude ballooning. For instance, when used in a balloon system, the telescoping support structure may be suspended between two objects such as an upper payload structure and a lower payload structure. As another example, the telescoping support structure may be suspended between a balloon envelope and a payload which, in some examples, may include an upper and a lower payload structure.