Likely to be a hydrogen fuel source (record flight time so far is ~12 hours) - https://cryogenicsociety.org/36975/news/hydrogen_fuel_cell-powered_drone_sets_new

Likely to be a hydrogen fuel source (record flight time so far is ~12 hours) - https://cryogenicsociety.org/36975/news/hydrogen_fuel_cell-powered_drone_sets_new_flight_time_record/ https://cryogenicsociety.org/36975/news/hydrogen_fuel_cell-p...