Aspects of the disclosure relate to fabricating high-altitude balloons having a prebuilt parachute overlying the surface of the balloon envelope to handle catastrophic envelope failures. The balloon envelope is formed from a number of gore panels. Tendons are positioned adjacent to corresponding ones of the gore panels. Each tendon is configured to carry a load caused by pressurized lifting gas within the balloon envelope. The parachute is affixed to at least some of the tendons, and covers at least a portion of the balloon envelope adjacent to the apex of the envelope. The parachute may be sewn onto the tendons. An outer surface of the parachute is covered with a UV-protective material. For instance, an aluminum coating may be vapor-deposited onto the parachute's outer surface. An IR-reflective material may cover an inner surface of the parachute.

Aspects of the disclosure relate to fabricating high-altitude balloons having a prebuilt parachute overlying the surface of the balloon envelope to handle catastrophic envelope failures. The balloon envelope is formed from a number of gore panels. Tendons are positioned adjacent to corresponding ones of the gore panels. Each tendon is configured to carry a load caused by pressurized lifting gas within the balloon envelope. The parachute is affixed to at least some of the tendons, and covers at least a portion of the balloon envelope adjacent to the apex of the envelope. The parachute may be sewn onto the tendons. An outer surface of the parachute is covered with a UV-protective material. For instance, an aluminum coating may be vapor-deposited onto the parachute's outer surface. An IR-reflective material may cover an inner surface of the parachute.

A high altitude lighter-than-air (LTA) system can include a zero-pressure balloon (ZPB) attached in tandem with one or more variable ballast air super-pressure balloons (SPB). The ZPB provides lift for the system while the SPB uses a centrifugal compressor to provide a variable amount of ballast air by pumping in or expelling out ambient air. A solar array coupled with an elongated ladder assembly can be coupled to a payload support for a payload carried by the LTA system. 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 efficient high altitude station-keeping approaches, are made possible with the LTA system.

A high altitude lighter-than-air (LTA) system can include a zero-pressure balloon (ZPB) attached in tandem with one or more variable ballast air super-pressure balloons (SPB). The ZPB provides lift for the system while the SPB uses a centrifugal compressor to provide a variable amount of ballast air by pumping in or expelling out ambient air. A solar array coupled with an elongated ladder assembly can be coupled to a payload support for a payload carried by the LTA system. 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 efficient high altitude station-keeping approaches, are made possible with the LTA system.

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.

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.