Unmanned aerial vehicle with inflatable membrane

An unmanned aerial vehicle (UAV) comprising:

• a propulsion system comprising a first vertical takeoff propeller that is configured to lift the UAV;
• a compressed gas chamber configured to contain a gas that is lighter than air;
• an inflatable membrane configured to be inflated with gas from the compressed gas chamber;
• a stabilization mechanism that maintains the membrane at a sufficient distance from the first vertical takeoff propeller to avoid contact with the first vertical takeoff propeller while the UAV is flying;
• and
• a computing system comprising:
• one or more processors;
• and
• a memory coupled to the one or more processors and storing program instructions that when executed by the one or more processors cause the one or more processors to at least:
• inflate the membrane with gas from the compressed gas chamber;
• fly the UAV along an at least ascending segment of a travel path with the membrane inflated;
• deflate the membrane;
• and
• fly the UAV along a subsequent segment of the travel path with the membrane deflated.

An unmanned aerial vehicle (UAV) comprising:

• a propulsion system comprising one or more vertical takeoff propellers that are configured to lift the UAV;
• an inflatable membrane;
• a compressed buoyant gas;
• an inflating mechanism configured to inflate the membrane through expansion of the compressed buoyant gas;
• and
• a stabilization mechanism that maintains the membrane at a sufficient distance from the one or more vertical takeoff propellers to avoid contact with the one or more vertical takeoff propellers while the UAV is flying;
• wherein a density of an expanded buoyant gas in the membrane is lower than a density of ambient air,
• wherein the membrane remains inflated during at least an ascending portion of a travel path of the UAV;
• and wherein the membrane remains deflated during at least a second portion of the travel path of the UAV.