An example reusable high-altitude balloon system includes a balloon with a first end supporting a payload and a second end with an aperture and an apex fitting that is positioned within the aperture. A clamp applies a pressure to a plurality of pleated folds formed in the perimeter of the aperture around the apex fitting to form an air-tight seal against the balloon at the perimeter of the aperture. The reusable high-altitude balloon system further includes control circuitry that controllably releases the apex fitting from the balloon to initiate a descent sequence.

Described herein are features for a high altitude lighter-than-air (LTA) system and associated methods. A zero-pressure balloon (ZPB) is attached in tandem with one or more air super-pressure balloons (SPB). The ZPB provides lift for the system while the SPB may provide a variable amount of ballast air by pumping in or expelling out ambient air. Various advanced performance targets relating to ascent rate, descent rate, range and maximum altitude are achievable with various scaled versions of the basic design of the LTA system. Advanced navigation and control techniques, such as more efficient high altitude station-keeping approaches, made possible with the LTA system are also described.

Described herein are features for a high altitude lighter-than-air (LTA) system and associated methods. A zero-pressure balloon (ZPB) is attached in tandem with one or more air super-pressure balloons (SPB). The ZPB provides lift for the system while the SPB may provide a variable amount of ballast air by pumping in or expelling out ambient air. Various advanced performance targets relating to ascent rate, descent rate, range and maximum altitude are achievable with various scaled versions of the basic design of the LTA system. Advanced navigation and control techniques, such as more efficient high altitude station-keeping approaches, made possible with the LTA system are also described.

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.

Features for a high altitude lighter-than-air (LTA) system and associated methods. A zero-pressure balloon (ZPB) is attached in tandem with one or more variable ballast air super-pressure balloons (SPB) having a continuous skin and multiple SPB compartments. The ZPB provides lift for the system while the multi-compartment SPB uses a centrifugal compressor to provide a variable amount of ballast air by pumping in or expelling out ambient air. Various performance targets relating to ascent rate, descent rate, range and maximum altitude are achievable with various scaled versions of the basic design of the LTA system. Navigation and control techniques, such as high altitude station-keeping approaches, are made possible with the LTA system.

Features for a high altitude lighter-than-air (LTA) system and associated methods. A zero-pressure balloon (ZPB) is attached in tandem with one or more variable ballast air super-pressure balloons (SPB) having a continuous skin and multiple SPB compartments. The ZPB provides lift for the system while the multi-compartment SPB uses a centrifugal compressor to provide a variable amount of ballast air by pumping in or expelling out ambient air. Various performance targets relating to ascent rate, descent rate, range and maximum altitude are achievable with various scaled versions of the basic design of the LTA system. Navigation and control techniques, such as high altitude station-keeping approaches, are made possible with the LTA system.

Aspects of the disclosure relate to flight termination systems for aerial vehicles having envelopes. For instance, a flight termination system may include one or more heat sources mounted on the top plate and oriented towards envelope material of the envelope. The one or more heat sources may each include a gas generator configured to generate gas of sufficient temperature to melt the envelope material and vent lift gas from the envelope. The flight termination system may also include a drag device arranged at the top plate which may be being configured to provide stability to the envelope during descent.

Aspects of the disclosure relate to flight termination systems for aerial vehicles having envelopes. For instance, a flight termination system may include one or more heat sources mounted on the top plate and oriented towards envelope material of the envelope. The one or more heat sources may each include a gas generator configured to generate gas of sufficient temperature to melt the envelope material and vent lift gas from the envelope. The flight termination system may also include a drag device arranged at the top plate which may be being configured to provide stability to the envelope during descent.

An example reusable high-altitude balloon system includes a control system configured to initiate a termination sequence by separating a payload from an Earth-facing end of the balloon body. Separation of the payload from the balloon body generates a torque that causes the balloon body to invert and release lift gas through a vent duct, initiating a flight termination sequence that facilitates landing of the reusable balloon system without destroying the balloon body.