Active valve for throttling ascent rate

A valve assembly adapted for controlling an altitude of an unmanned aerial vehicle, comprising:

• a shuttle of a valve assembly adapted to translate from a first position to a second position wherein translating the shuttle includes causing a motor associated with the valve assembly to rotate in a first direction to cause a corresponding rotation of a screw of a screw assembly coupled to the motor, wherein a portion of the screw assembly is disposed within a bore defined on the shuttle;
• an impeller adapted to rotate in the first direction to draw air through an inlet tube of the valve assembly and into an interior portion of a ballonet that is disposed within an interior portion of a balloon, wherein the impeller is disposed downstream of the valve assembly;
• and
• wherein adjusting the position of the shuttle relative to the inlet tube adjusts an amount of fluid permitted to be drawn into the inlet tube and adjusts a descent rate of the balloon.

An unmanned aerial vehicle, comprising:

• a balloon having a ballonet disposed therein configured to retain a ballasting gas;
• an altitude control system;
• a diffuser carried by the balloon and in fluid communication with the ballonet;
• and
• a valve assembly in fluid communication with the diffuser;
• an inlet tube included in the valve assembly extending between a first and a second end portion;
• a shuttle partially disposed within the inlet tube and configured to be placed in a first position where an outer surface of the shuttle abuts a portion of the inlet tube and a second position wherein the outer surface of the shuttle is disposed in spaced relation to the inlet tube;
• a base plate extending between first and second end portions, the first end portion of the base plate defining a cavity therein;
• a screw assembly disposed within the cavity of the base plate, wherein a portion of the screw assembly is disposed within a bore defined on the shuttle;
• and
• a spacer block interposed between the second end portion of the inlet tube and the first end portion of the base plate, the spacer block configured to maintain the inlet tube and the base plate in spaced relation to one another.