Research and build for a sub 250 drone capable of running Ardupilot in all of its functions (including autnomous flight) to maximize flight time.
Weight minimization is key to maximize flight endurance. Batteries represent the bigger % of total weight in such a build. In order to stay below the 250 grams limit (thank you @!_* regulators), 2S voltage is practically a constraint. Therefore research has to be invested in ESCs and flight controllers able to operate under such small voltage. Li-Ion appears to be the current only battery having the best capacity/weight ratio to build a lightweight 2S battery.
Then comes the frame optimization. Most drone frames are overbuilt on purpose in a hype to resist hypothetical circumstances that never happen or are simply unrealistic. Therefore there is a huge oportunity in researching frame design improvements that minimize weight while still maintaining enough rigidity and solidity.
Frame used in this video comes as a result of many hours and discussions in our private international research group of experts. In particular I would like to thank and put Ryan forward (see quadstardrones) who holds the current worldwide record of designing and making the fastest racer drones.