A revolutionary electronic aircraft propulsion system inspired by Star Trek has been tested on a working model for the first time. The five metre (16ft) wingspan glider-like plane has no propellers, turbines or any other moving parts, and is completely silent.
Instead, an “ionic wind” of colliding electrically charged air molecules provides the thrust needed to make it fly. In tests, the battery-powered unmanned aircraft, which weighs just five pounds, managed sustained flight of 60 metres (197ft) at an average height of just 0.47 metres (18 inches).
But its inventors believe that, like the early experiments of the Wright brothers more than 100 years ago, such small beginnings will eventually transform the face of aviation. In the near future, ion wind propulsion could be employed to power quiet drones, the team predicts.
Further down the line, the technology could be paired with more conventional propulsion systems to produce highly fuel efficient hybrid passenger planes.
Lead researcher Dr Steven Barrett, from Massachusetts Institute of Technology in the US, said: “This is the first-ever sustained flight of a plane with no moving parts in the propulsion system.
“This has potentially opened new and unexplored possibilities for aircraft which are quieter, mechanically simpler, and do not emit combustion emissions.”
He revealed that he was partly inspired by the TV sci-fi series Star Trek, which he watched avidly as a child.
He was especially impressed by the show’s futuristic shuttle crafts that skimmed through the air producing hardly any noise or exhaust.
“This made me think, in the long-term future, planes shouldn’t have propellers and turbines,” said Dr Barrett. “They should be more like the shuttles in Star Trek that have just a blue glow and silently glide.”
The test aircraft, described in the journal Nature, carries an array of thin wires strung beneath the front end of its wings. A high voltage current passed through the wires strips negatively charged electrons from surrounding air molecules. This produces a cloud of positively charged ionised air molecules that are attracted to another set of negatively charged wires at the back of the plane.
As they flow towards the negative charge, the ions collide millions of times with other air molecules, creating the thrust that pushes the aircraft forward.
One of the biggest challenges was designing a power supply that would generate 40,000 volts from the plane’s battery output. The team is working on ways of producing more ionic wind with less voltage.
Test flights were made across the gymnasium at MIT’s duPont Athletic Centre, the largest indoor space the scientists could find.
Dr Barrett said: “It took a long time to get here. Going from the basic principle to something that actually flies was a long journey of characterising the physics, then coming up with the design and making it work. “Now the possibilities for this kind of propulsion system are viable.”