Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A riser release system controllably lands a descending flight vehicle having a parafoil or canopy. The system has control lines and riser lines attached to the parafoil or canopy. The other end of the riser lines are attached to an upper portion of a release structure; a lower portion of the release structure is connected to the payload; and a coupling mechanisms releasably couples the upper and lower portions. When the upper and lower portions are decoupled, a distance control device controls and limits the distance of separation between the two portions, and a rate control device controls the rate of separation. Separation causes the riser lines to increase the distance between the payload and canopy, further causing the canopy to flare and decrease the rate of descent of the flight vehicle.

Abstract: 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.

Abstract: A method for calibrating a synthetic jet ejector is provided. The method includes (a) taking a first measurement DCR0 of the DC resistance of the coil; (b) adjusting the actuator drive voltage Vd to achieve a desired maximum displacement dmax1 at a frequency f1; (c) measuring the input current Iin and input voltage Vin; (d) calculating the back electromagnetic frequency BEMF, wherein BEMF=Vin?Iin*DCR; and (e) storing the calculated value of BEMF in a memory device associated with the synthetic jet actuator.

Abstract: A method for calibrating a synthetic jet ejector is provided which comprises (a) taking a first measurement DCR0 of the DC resistance of the coil; (b) adjusting the actuator drive voltage Vd to achieve a desired maximum displacement dmax1 at a frequency f1; (c) measuring the input current Iin and input voltage Vin; (d) calculating the back electromagnetic frequency BEMF, wherein BEMF=Vin?Iin*DCR; and (e) storing the calculated value of BEMF in a memory device associated with the synthetic jet actuator.