Supplementing energy storage of an in-flight solar-powered UAV by casting light from a secondary in-flight UAV

A method of charging a battery of a first aircraft in flight at night, wherein the first aircraft is equipped with solar cells that convert light into electricity for charging the battery, the method comprising:

• flying a second aircraft in proximity to the first aircraft when the first aircraft is in flight at night;
• and
• while flying the second aircraft in proximity to the first aircraft when the first aircraft is in flight at night, (i) shining an incoherent light from the second aircraft onto the solar cells of the first aircraft for conversion of the incoherent light by the solar cells into electricity for charging the battery and (ii) tracking a position of the first aircraft in relation to a position of the second aircraft and, based on the tracking, dynamically adjusting direction of the incoherent light to continue to shine the incoherent light onto the solar cells of the first aircraft for conversion of the incoherent light by the solar cells into electricity for charging the battery.

A system for charging a battery of a first unmanned aerial vehicle (UAV) while the first UAV is in flight, wherein the first UAV is equipped with solar cells that convert light into electricity for charging the battery, the system comprising:

• a second UAV equipped with a directional light source;
• and
• a controller configured (i) to cause the second UAV to fly in proximity to the first UAV while the first UAV is in flight and (ii) while the second UAV is flying in proximity to the first UAV in flight, to cause the directional light source to cast incoherent light onto the first UAV for conversion of the light by the solar cells into electricity for charging the battery.