Abstract: Aspects of the technology relate to propulsion systems for high altitude, long duration balloons, such as balloons that operate in the stratosphere for weeks, months or longer. A propeller assembly is used to provide lateral directional adjustments, which allows the balloon to spend more time over a desired region, reduce the return time to the desired region, reduce fleet overprovisioning, and increases the safety case by additional controls and avoidance abilities. A control assembly manages operation of the propeller assembly, including setting the pointing direction, speed of rotation and determining when to turn on the propeller and for how long. The propulsion system including the control and propeller assemblies is rotatable around a connection member of the balloon. Such rotation is independently adjustable from any rotation of the balloon's payload. The propeller blades may be made of plastic, which reduces weight and cost while providing sufficient speed at stratospheric altitudes.

Abstract: Aspects of the technology relate to lateral propulsion systems in lighter-than-air (LTA) platforms configured to operate in the stratosphere. One or more motor assemblies are used to actuate the lateral propulsion system and to make directional changes, for instance using one or more propellers. This can include a pointing axis motor assembly for orienting the lateral propulsion system along a particular heading, and a drive motor assembly for causing a propeller assembly or other propulsion mechanism to turn on and off Corrective actions may be necessary to adjust the alignment of the lateral propulsion system. A stepper motor control module may be used to control operation of the pointing axis motor assembly, for instance by causing it to rotate in a clockwise (or counterclockwise) direction. A motor current control approach may be used, in which the motor voltage is adjusted until a measured motor current reaches a selected current level.

Abstract: Aspects of the technology relate to a braking assembly for a lateral propulsion system of a high altitude platform (HAP) configured to operate in the stratosphere. Power is supplied to a propeller assembly as needed during lateral propulsion so that the HAP can move to a desired location or remain on station. When lateral propulsion is not needed, power is no longer supplied to the propeller assembly and it may slowly cease rotating. However, in certain situations, it may be necessary to cause the propeller assembly to stop rotating as soon as possible. This can include an unplanned descent. Rapid braking can avoid the propeller blades from entangling in the envelope, parachute or other parts of the HAP. A reusable brake is employed to prevent uncontrolled rotation of the propeller on descent, or otherwise to prevent the propeller from spinning freely when not being used to propel the HAP laterally.

Abstract: Aspects of the technology relate to altitude control and lateral propulsion systems in lighter-than-air (LTA) platforms configured to operate in the stratosphere. For instance, an LTA platform may include an envelope filled with lift gas and a payload for providing telecommunication or video services. A fault or failure condition with one or more components of these systems, or with the envelope of the LTA platform itself, can prevent a high altitude platform (HAP) from operating as intended, or otherwise reduce its useful life. Onboard systems are configured to handle adverse conditions, such as a fault or failure of the envelope, an altitude control system component, or the lateral propulsion system. This may be done according to one or more ranked lists of adverse operational conditions. Different conditions may map to different corrective actions, which may be prioritized in importance, for instance to reduce the chance of catastrophic system failure.

Abstract: Aspects of the technology relate to propulsion systems for high altitude, long duration balloons, such as balloons that operate in the stratosphere for weeks, months or longer. A propeller assembly is used to provide lateral directional adjustments, which allows the balloon to spend more time over a desired region, reduce the return time to the desired region, reduce fleet overprovisioning, and increases the safety case by additional controls and avoidance abilities. A control assembly manages operation of the propeller assembly, including setting the pointing direction, speed of rotation and determining when to turn on the propeller and for how long. The propulsion system including the control and propeller assemblies is rotatable around a connection member of the balloon. Such rotation is independently adjustable from any rotation of the balloon's payload. The propeller blades may be made of plastic, which reduces weight and cost while providing sufficient speed at stratospheric altitudes.

Abstract: A magnetic belt used in magnetic sensing device for measuring a rotation speed of a rotating shaft comprises a belt body adapted to be wound around a perimeter of the shaft in the shape of a circle and fixed thereto. The belt body includes a row of toothed protrusions arranged on a first outer surface of the belt body. With the belt body arranged on the shaft, the toothed protrusions are evenly spaced around a circumference of the rotation shaft.

Abstract: Aspects of the technology relate to lateral propulsion systems in lighter-than-air (LTA) platforms configured to operate in the stratosphere. One or more motor assemblies are used to actuate the lateral propulsion system and to make directional changes, for instance using one or more propellers. This can include a pointing axis motor assembly for orienting the lateral propulsion system along a particular heading, and a drive motor assembly for causing a propeller assembly or other propulsion mechanism to turn on and off Corrective actions may be necessary to adjust the alignment of the lateral propulsion system. A stepper motor control module may be used to control operation of the pointing axis motor assembly, for instance by causing it to rotate in a clockwise (or counterclockwise) direction. A motor current control approach may be used, in which the motor voltage is adjusted until a measured motor current reaches a selected current level.

Abstract: Aspects of the technology relate to propulsion systems for high altitude, long duration balloons, such as balloons that operate in the stratosphere for weeks, months or longer. A propeller assembly is used to provide lateral directional adjustments, which allows the balloon to spend more time over a desired region, reduce the return time to the desired region, reduce fleet overprovisioning, and increases the safety case by additional controls and avoidance abilities. A control assembly manages operation of the propeller assembly, including setting the pointing direction, speed of rotation and determining when to turn on the propeller and for how long. The propulsion system including the control and propeller assemblies is rotatable around a connection member of the balloon. Such rotation is independently adjustable from any rotation of the balloon's payload. The propeller blades may be made of plastic, which reduces weight and cost while providing sufficient speed at stratospheric altitudes.

Abstract: Aspects of the technology relate to a braking assembly for a lateral propulsion system of a high altitude platform (HAP) configured to operate in the stratosphere. Power is supplied to a propeller assembly as needed during lateral propulsion so that the HAP can move to a desired location or remain on station. When lateral propulsion is not needed, power is no longer supplied to the propeller assembly and it may slowly cease rotating. However, in certain situations, it may be necessary to cause the propeller assembly to stop rotating as soon as possible. This can include an unplanned descent. Rapid braking can avoid the propeller blades from entangling in the envelope, parachute or other parts of the HAP. A reusable brake is employed to prevent uncontrolled rotation of the propeller on descent, or otherwise to prevent the propeller from spinning freely when not being used to propel the HAP laterally.

Abstract: Aspects of the technology relate to propulsion systems for high altitude, long duration balloons, such as balloons that operate in the stratosphere for weeks, months or longer. A propeller assembly is used to provide lateral directional adjustments, which allows the balloon to spend more time over a desired region, reduce the return time to the desired region, reduce fleet overprovisioning, and increases the safety case by additional controls and avoidance abilities. A control assembly manages operation of the propeller assembly, including setting the pointing direction, speed of rotation and determining when to turn on the propeller and for how long. The propulsion system including the control and propeller assemblies is rotatable around a connection member of the balloon. Such rotation is independently adjustable from any rotation of the balloon's payload. The propeller blades may be made of plastic, which reduces weight and cost while providing sufficient speed at stratospheric altitudes.