Abstract: Aspects of the technology relate to temperature regulation for high altitude, long duration balloons, such as balloons that operate in the stratosphere for weeks, months or longer. A balloon covering overlays the balloon envelope. The material properties and configuration of the balloon covering are selected to enable it to automatically cover or expose portions of the envelope depending on environmental conditions. The covering has multiple layers of materials with different coefficients of thermal expansion (CTE). The layers are chosen to have significantly different CTEs, and flaps are created in the envelope such that depending on the temperature, the flaps will either lie flat on the envelope or curl away from the envelope. In the former case, the flaps help to retain heat in the envelope, such as during nighttime operation. Conversely, in the latter case, the flaps permit heat to escape from the envelope, such as during daytime operation.

Abstract: Systems and methods for extending life of an apparatus, such as a balloon, using electrolysis. A ballast liquid is carried or harvested and, when desired, is electrolyzed using an on-board electrolyzer to generate lift gas, rather than simply being dumped as traditional ballast. However, the ballast liquid may also be dumped, if necessary. A valve may be provided to enable safe dumping of the ballast liquid. The ballast liquid may be water, a water-methanol mixture, or other suitable ballast liquid. The ballast liquid may be stored in a container associated with the balloon prior to launch or may be harvested from the atmosphere while the balloon is in-flight. Features may be provided to maintain the ballast liquid in a liquid state. The lift gas mixture within the balloon is maintained non-flammable.

Abstract: Aspects of the technology relate to temperature regulation for high altitude, long duration balloons, such as balloons that operate in the stratosphere for weeks, months or longer. A balloon covering overlays the balloon envelope. The material properties and configuration of the balloon covering are selected to enable it to automatically cover or expose portions of the envelope depending on environmental conditions. The covering has multiple layers of materials with different coefficients of thermal expansion (CTE). The layers are chosen to have significantly different CTEs, and flaps are created in the envelope such that depending on the temperature, the flaps will either lie flat on the envelope or curl away from the envelope. In the former case, the flaps help to retain heat in the envelope, such as during nighttime operation. Conversely, in the latter case, the flaps permit heat to escape from the envelope, such as during daytime operation.

Abstract: Systems and methods for extending life of an apparatus, such as a balloon, using electrolysis. A ballast liquid is carried or harvested and, when desired, is electrolyzed using an on-board electrolyzer to generate lift gas, rather than simply being dumped as traditional ballast. However, the ballast liquid may also be dumped, if necessary. A valve may be provided to enable safe dumping of the ballast liquid. The ballast liquid may be water, a water-methanol mixture, or other suitable ballast liquid. The ballast liquid may be stored in a container associated with the balloon prior to launch or may be harvested from the atmosphere while the balloon is in-flight. Features may be provided to maintain the ballast liquid in a liquid state. The lift gas mixture within the balloon is maintained non-flammable.

Abstract: The present disclosure provides a thermal control apparatus for controlling temperatures in a payload of a balloon. The thermal control apparatus includes a plurality of heat pipes. A first heat pipe from the plurality of heat pipes has a first end and a second end and contains working fluid. A heat source is in thermal communication with the first heat pipe. The heat source is configured to heat the working fluid in the first heat pipe. A second heat pipe from the plurality of heat pipes contains working fluid and a portion of the second heat pipe is positioned a predetermined distance from the first heat pipe. The predetermined distance allows for a heat exchange from the first heat pipe to the second heat pipe. This heat exchange includes heat drawn away from the heat source.

Abstract: Systems and devices may include a thermal management device that includes a high emissivity material. The high emissivity material is configured to have a high emissivity with respect to wavelengths of electromagnetic radiation in a thermal infrared spectrum. The thermal management device is arrangeable on a surface of a component of a stratospheric aerial vehicle. The thermal management device is configured such that when arranged on the component of the stratospheric aerial vehicle during flight, a first side of the thermal management device faces substantially upward with respect to ground, and the second side of the thermal management device faces substantially downward with respect to the ground. The second side is shaped to retain air that is warmer than an ambient air temperature at a stratospheric altitude.