Birds stay aloft for hours without flapping, sensing the air around them and adjusting their wings to ride invisible columns of rising heat. Most drones are still blind to all of it. Nisan is teaching fixed-wing drones to find and ride thermals autonomously, turning free energy in the atmosphere into hours of additional flight time. His control software is built and validated, and its pressure-sensing skin has been designed. Now he is taking it out of simulation and into the sky.