Battery flywheel for a high-altitude balloon

A flywheel battery, comprising:

• a shaft defining a spin axis;
• a rotor mechanically coupled to the shaft, wherein the rotor is configured to rotate about the spin axis, wherein the rotor comprises at least one battery configured to store electrical energy, wherein the rotation of the rotor about the spin axis comprises kinetic mechanical energy;
• and
• a mount mechanically coupled to a balloon, wherein the mount comprises at least one stator, wherein the at least one battery is configured to provide electrical power to at least one sub-system of the balloon.

A non-transitory computer readable medium having stored therein instructions executable by a computing device to cause the computing device to perform functions comprising:

• causing a system to convert, in a balloon, first electrical energy into kinetic mechanical energy, wherein the balloon comprises a flywheel battery, wherein the flywheel battery is configured to rotate about a spin axis substantially parallel to a ground surface of the earth, wherein the kinetic mechanical energy comprises a rotational motion of the flywheel battery;
• causing the flywheel battery to store, using the rotational motion of the flywheel battery, the kinetic mechanical energy for a finite period of time;
• causing the flywheel battery to perform at least one of:
• i) converting at least a portion of the stored kinetic mechanical energy into second electrical energy;
• ii) stabilizing at least one motion of the balloon based on the rotational motion of the flywheel battery;
• iii) rotating the balloon substantially about a balloon axis substantially perpendicular to the ground surface of the earth.

A method, comprising:

• rotating a flywheel about a spin axis, wherein the flywheel is mechanically coupled to a balloon payload, wherein the balloon payload comprises an optical-communication component, wherein the optical-communication component has a current pointing axis, wherein the optical-communication component is operable to communicate with a correspondent device via a free-space optical link;
• determining an updated pointing axis so as to maintain the free-space optical link;
• determining a corrective gyroscopic torque so as change the current pointing axis to the updated pointing axis;
• generating the corrective gyroscopic torque by changing the spin axis;
• and
• enabling the balloon payload to move in response to the corrective gyroscopic torque.