A balloon system includes a balloon having a balloon membrane extending between an upper apex and a lower apex opening. The lower apex opening extends through the balloon membrane at a balloon lip. A ballonet is within the balloon. The ballonet is coupled with the balloon membrane at the lower apex opening. The ballonet includes a lower ballonet panel having a lower perimeter edge and a ballonet orifice extending through the lower ballonet panel at a ballonet lip and an upper ballonet panel having an upper perimeter edge. The upper and lower ballonet panels are coupled along the respective upper and lower perimeter edges. A lower apex fitting couples the ballonet with the balloon at the balloon lip of the lower apex opening.

Aspects described herein relate to an apparatus, system, and method for the airborne launch of inflatable, lighter-than-air devices from aircraft. In some instances, a container comprising a drag parachute and a main parachute assembly may be deployed from an aircraft. Drag forces on the container may cause the drag parachute to be expelled from the container. Drag forces on the drag parachute may cause the main parachute assembly to be expelled from the container. The main parachute assembly may include a canopy with an opening and a release channel connecting the opening with the container. The container may further include a balloon inflation mechanism, which may be used to inflate one or more balloon envelopes. The one or more balloon envelopes, after being inflated, may be configured to be released from the container, traverse the release channel, and exit the main parachute assembly through the opening.

A structural system for lifting cells, constructed of modular, lightweight framing supporting thin, lightweight, single-ply or laminated, air-impermeable membranes, that maintain near constant-volume under low pressure for aerostatic lift in lighter-than-air aircraft; a system for controlling that aerostatic lift in a single or a plurality of such lifting cells, using electrically-powered vacuum pumps and valves; and a system for recovering electrical energy expended during ascent by using the inflow of air into the lifting cells during descent to generate electricity.

A structural system for lifting cells, constructed of modular, lightweight framing supporting thin, lightweight, single-ply or laminated, air-impermeable membranes, that maintain near constant-volume under low pressure for aerostatic lift in lighter-than-air aircraft; a system for controlling that aerostatic lift in a single or a plurality of such lifting cells, using electrically-powered vacuum pumps and valves; and a system for recovering electrical energy expended during ascent by using the inflow of air into the lifting cells during descent to generate electricity.

Described herein are features for a high altitude lighter-than-air (LTA) system and associated methods. The LTA may include one or more super-pressure balloons (SPB). One or more of the SPB's may include one or more interior volumes. One or more of the interior volumes may be configured to receive an LTA gas therein to supplement the free lift of the LTA system. There may be an adjustable valve or vent to release the LTA gas. One or more of the interior volumes may be configured to receive ambient air to provide a variable downward force. The SPB may use a compressor to pump in ambient air. The compressor or another valve may release ambient air to decrease the downward force. A zero-pressure balloon (ZPB) may be attached with the one or more SPB's. The ZPB may supplement lift for the system.

Described herein are features for a high altitude lighter-than-air (LTA) system and associated methods. The LTA may include one or more super-pressure balloons (SPB). One or more of the SPB's may include one or more interior volumes. One or more of the interior volumes may be configured to receive an LTA gas therein to supplement the free lift of the LTA system. There may be an adjustable valve or vent to release the LTA gas. One or more of the interior volumes may be configured to receive ambient air to provide a variable downward force. The SPB may use a compressor to pump in ambient air. The compressor or another valve may release ambient air to decrease the downward force. A zero-pressure balloon (ZPB) may be attached with the one or more SPB's. The ZPB may supplement lift for the system.

Methods and apparatus are disclosed for an apex fitting for securing to a high altitude balloon. An example apparatus involves: (a) a base plate defining an opening, where the base plate is configured to be securable to an exterior of a balloon envelope, (b) at least one stud coupled to the base plate and configured to be securable to a tendon, (c) a retention ring defining at least one opening configured to receive the at least one stud, (d) a fill-port body defining a cavity, wherein a flange is coupled to the fill-port body, wherein the fill-port body is arranged coaxially with and extends through the opening of the base plate such that the flange lies adjacent to the bottom surface of the base plate, and (e) a locking body coupled to the fill-port body, wherein the locking body defines an opening arranged coaxially with the fill-port body.

Methods and apparatus are disclosed for an apex fitting for securing to a high altitude balloon. An example apparatus involves: (a) a base plate defining an opening, where the base plate is configured to be securable to an exterior of a balloon envelope, (b) at least one stud coupled to the base plate and configured to be securable to a tendon, (c) a retention ring defining at least one opening configured to receive the at least one stud, (d) a fill-port body defining a cavity, wherein a flange is coupled to the fill-port body, wherein the fill-port body is arranged coaxially with and extends through the opening of the base plate such that the flange lies adjacent to the bottom surface of the base plate, and (e) a locking body coupled to the fill-port body, wherein the locking body defines an opening arranged coaxially with the fill-port body.

A lighter than air platform an unfinned envelope having two or more propulsion elements coupled with the unfinned envelope proximate to the center of gravity. At least one navigation sensor is configured to monitor an actual flight path of the unfinned envelope, and at least one perturbation sensor is configured to monitor one or more perturbations of the unfinned envelope. A navigation controller is configured to guide the unfinned envelope with coordinated propulsion of the two or more propulsion elements. The navigation controller includes a navigation comparator that compares the actual flight path with a specified flight path of the unfinned envelope and determine a navigation instruction. A perturbation comparator compares the navigation instruction with the monitored one or more perturbations to determine a perturbation compensation. A propulsion coordinator controls propulsion values of each of the propulsion elements based on the navigation instruction and the perturbation compensation.

A balloon system including a balloon envelope and a ballonet positioned within the balloon envelope, and a plurality of internal panels extending within the balloon envelope between the ballonet and the balloon envelope, wherein the plurality of internal panels are attached to an outside of the ballonet and attached to an inside of the balloon envelope to support the ballonet within the balloon envelope during inflation of the ballonet.