A balloon is provided having an exostructure comprised of hollow struts or rods and an envelope positioned over the exostructure, and a pump for pumping air out of the balloon to create an air pressure differential between the pressure inside the envelope and the atmospheric pressure outside the envelope, a control system configured to allow air to flow into the envelope to control the altitude of the balloon, and to operate the pump to pump air out of the envelope to control the altitude of the balloon, wherein the material of the envelope is arranged so as to sag between the struts or rods and form at least one catenary surface when there is an air pressure differential between the pressure inside of the balloon envelope and the atmospheric pressure outside the envelope.

Described herein are features for a riser release flaring system for parafoils and other descent flight vehicles for controlled descent and landing of the flight vehicle. The descent flight vehicle may have a payload suspended by a canopy. The descent flight vehicle may be released from a high altitude lighter-than-air (LTA) system, from another system, or may not be associated with any other flight system. The riser release auto flare system is used with the descent system, such as the parafoil, for controlled and safe landing of the payload. Riser lines are released at a controlled rate and for a fixed distance to automatically cause the payload to pull control lines to flare the parafoil and slow a descent and/or forward speed of the vehicle. The riser lines may be released in response to the descent system satisfying a landing criterion, such as altitude.

Innovative new methods in connection with lighter-than-air free floating platforms, of facilitating legal transmitter operation, platform flight termination when appropriate, environmentally acceptable landing, and recovery of these devices are provided. Especially, termination of radio transmissions and flight related to regional, governmental and international border requirements, regulations and laws. The new methods comprise specific criteria, detection of the criteria and elements of operation for reducing or preventing illegal transmissions, for producing rapid descend to the ground, for environmentally acceptable landing and for facilitating recovery all with improved safety and enhanced compliance with known regulations.

Innovative new methods in connection with lighter-than-air free floating platforms, of facilitating legal transmitter operation, platform flight termination when appropriate, environmentally acceptable landing, and recovery of these devices are provided. Especially, termination of radio transmissions and flight related to regional, governmental and international border requirements, regulations and laws. The new methods comprise specific criteria, detection of the criteria and elements of operation for reducing or preventing illegal transmissions, for producing rapid descend to the ground, for environmentally acceptable landing and for facilitating recovery all with improved safety and enhanced compliance with known regulations.

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, providing an opaque or otherwise light-reflective layer with low emissivity that blocks or reflects optical and/or infrared light. Heat from within the envelope is reflected back from the covering toward the envelope, while light from the sun is reflected back towards the environment. An active venting system is employed to draw in cooler ambient air from the external environment while expelling warmer air from within the envelope. Vent and air intake assemblies of the active venting system are actuated in view of current and/or predicted balloon conditions to regulate internal balloon temperature. This approach reduces repeated pressure changes, which can put undue stress on the balloon envelope and adversely affect the operational lifespan of the system.

A towed atmospheric balloon system includes an atmospheric balloon including a quantity of lift gas and a neutral buoyancy towing system coupled with the atmospheric balloon. The neutral buoyancy towing system includes one or more towing thrusters configured to move the towed atmospheric balloon system in a neutrally buoyant condition between altitudes, and a power source operatively coupled with the towing thruster. Wherein a composite mass of the towed atmospheric balloon system includes component masses of the atmospheric balloon and the neutral buoyancy towing system, and the composite mass is static and neutral buoyancy is maintained with movement between altitudes. At differing altitudes the composite mass of the towed atmospheric balloon system is static and the system remains neutrally buoyant.

Described herein are features for high altitude lighter-than-air (LTA) balloon antenna systems and associated methods. One or more long wire communications antennas may be built into the balloon skin. The antenna may extend under, in, on or otherwise along one of the seams formed by connected edges of gores that define the balloon volume. The antenna may include an elongated electrical conductor with a length based on a desired communication frequency. The antenna may be secured with load tape along the seam. The antenna may be included in an LTA balloon system that includes multiple balloons connected in tandem, such as a zero-pressure balloon (ZPB) and one or more variable air ballast super-pressure balloons (SPB).

Described herein are features for high altitude lighter-than-air (LTA) balloon antenna systems and associated methods. One or more long wire communications antennas may be built into the balloon skin. The antenna may extend under, in, on or otherwise along one of the seams formed by connected edges of gores that define the balloon volume. The antenna may include an elongated electrical conductor with a length based on a desired communication frequency. The antenna may be secured with load tape along the seam. The antenna may be included in an LTA balloon system that includes multiple balloons connected in tandem, such as a zero-pressure balloon (ZPB) and one or more variable air ballast super-pressure balloons (SPB).

A flight vehicle includes a drone with a pair of shaped protrusions mechanically coupled to the drone. One of the shapes is a hollow lift-producing shape, such as being a balloon filed with a lighter-than-air gas, and the other of the shapes is below the drone. The shape below the drone may be a hollow shape that does not produce lift, for example being a balloon filled with air. The shapes may be similar in size and shape, so as to provide similar drag characteristics. The shapes may be opposite ends of a support, such as a stick, rod, or other (relatively) slender structure. The vehicle includes a payload, such as radar calibration equipment or an antenna. The drone may be used to counteract wind forces on the flight vehicle, and/or to otherwise position the flight vehicle.

A flight vehicle includes a drone with a pair of shaped protrusions mechanically coupled to the drone. One of the shapes is a hollow lift-producing shape, such as being a balloon filed with a lighter-than-air gas, and the other of the shapes is below the drone. The shape below the drone may be a hollow shape that does not produce lift, for example being a balloon filled with air. The shapes may be similar in size and shape, so as to provide similar drag characteristics. The shapes may be opposite ends of a support, such as a stick, rod, or other (relatively) slender structure. The vehicle includes a payload, such as radar calibration equipment or an antenna. The drone may be used to counteract wind forces on the flight vehicle, and/or to otherwise position the flight vehicle.