Abstract: Aspects of the disclosure relate to high altitude or stratospheric balloon systems. For instance, a stratospheric balloon system may include a an upper structure, a lower structure, a platform associated with the lower structure, a stack of solar panels positioned on the platform, each solar panel coupled to an adjacent solar panel, at least one tension element connected, at a first end thereof, to the upper structure and, at a second end thereof, to the platform, and a first flexible tension member coupled, at a first end thereof, to the upper structure and to foremost solar panel of the stack of solar panels. Solar panels may be stacked in a “Z-fold” configuration with either solar cells of the adjacent solar panels facing one another or the frames of the adjacent solar panels facing one another. In this configuration, the adjacent solar panels are connected by a hinge system.

Abstract: Aspects of the disclosure relate to high altitude or stratospheric balloon systems. For instance, a stratospheric balloon system may include a an upper structure, a lower structure, a platform associated with the lower structure, a stack of solar panels positioned on the platform, each solar panel coupled to an adjacent solar panel, at least one tension element connected, at a first end thereof, to the upper structure and, at a second end thereof, to the platform, and a first flexible tension member coupled, at a first end thereof, to the upper structure and to foremost solar panel of the stack of solar panels. Solar panels may be stacked in a “Z-fold” configuration with either solar cells of the adjacent solar panels facing one another or the frames of the adjacent solar panels facing one another. In this configuration, the adjacent solar panels are connected by a hinge system.

Abstract: A control system for terminating flight of a balloon having a balloon envelope is provided. The control system includes a shuttle that has one or more cutting blades. The cutting blades are configured to cut open the balloon envelope. A tubular track is attached to a section of the balloon envelope. This tubular track has a guiding portion arranged to receive and guide the shuttle along the track. The control system includes a type of releasable ballast attached to the shuttle. When the ballast is released, the ballast is configured to move the shuttle along the tubular track in order to cause at least one of the cutting blades to cut open a portion of the balloon envelope. This allows lift gas to escape from the balloon envelope.

Abstract: An apparatus for securing a plurality of tendons to a balloon includes a first and second plate and a cable long enough to extend around a circumference of the first plate. The first plate has a plurality of slots and one more mating ports. Each slot is configured to allow a given tendon from the plurality of tendons to extend through the first plate by inserting a tendon within the slot. The second plate has a surface with one or more mating members attached. Each mating member is configured to connect the first and second plates together by mating with at least one of the one or more mating ports. The cable is configured to pass between the first and second plates so as to couple with each tendon within the plurality of slots in order to secure the tendons to a balloon structure.

Abstract: A control system for terminating flight of a balloon having a balloon envelope is provided. The control system includes a shuttle that has one or more cutting blades. The cutting blades are configured to cut open the balloon envelope. A tubular track is attached to a section of the balloon envelope. This tubular track has a guiding portion arranged to receive and guide the shuttle along the track. The control system includes a type of releasable ballast attached to the shuttle. When the ballast is released, the ballast is configured to move the shuttle along the tubular track in order to cause at least one of the cutting blades to cut open a portion of the balloon envelope. This allows lift gas to escape from the balloon envelope.