"Low altitude" refers to airspace 1 kilometre (0.6 miles) above the surface of the Earth; the low-altitude economy encompasses all airborne economic activity within this sphere, including drones and flying cars. This has been an area of growing interest for countries around the world, with China's low-altitude economy having been predicted by one firm in March 2024 to hit 2 trillion yuan (then around US$280 billion) by 2030.