The first journey of an aircraft with an ion drive

IT IS NOTTIE unusual for technologies from science fiction to join the real world, with examples ranging from video phones, via artificial intelligence, to self-driving cars. The ion drive is another such. Ion drives purportedly propelled the evil Empire’s (twin ion engines) fighters in the original “Star Wars” movie. Real ion drives now reposition satellites and send space probes on interplanetary journeys. Surprisingly, according to a paper published this week in , they may have an earthly role, too. For the first time an aeroplane has flown powered by an ion drive.The reason for surprise is that an ion drive delivers only a tiny amount of thrust. This does not matter in the vacuum of space, because without friction to hold a spacecraft back, speed builds up gradually to a decent rate. On Earth, however, it had long been assumed that the atmosphere is too dense for an aircraft using an ion drive to get off the ground.