Visit tech startup Skydio’s headquarters on the San Francisco peninsula in California and you’re likely to find flying robots buzzing on the roof overhead. Docking stations with motorised covers open to allow small drones that resemble the TIE fighters from Star Wars films to take off; when each drone lands back again, they close. The drones can fly completely autonomously and without GPS, taking in data from onboard cameras and using AI to execute programmed missions and avoid obstacles. Skydio, with more than $740m in venture capital funding and a valuation of about $2.5bn, makes drones for the military along...