A University of Florida researcher is designing a flying saucer that uses plasma and surrounding air as its fuel to generate lift. The aircraft's skin will be studded with electrodes that ionize the air, converting it into plasma. Mechanical and aerospace engineering associate professor Subrata Royh hopes to have a six inch working prototype in the next year.
Using an onboard source of energy (such as a battery, ultracapacitor, solar panel or any combination thereof), the electrodes will send an electrical current into the plasma, causing the plasma to push against the neutral (noncharged) air surrounding the craft, theoretically generating enough force for liftoff and movement in different directions (depending on where on the craft's surface you direct the electrical current)…Theoretically, Roy says, the flying saucer can be as large as anyone wants to build it, because the design gives the aircraft balance and stability. In other words, this type of aircraft could someday be built large enough to ferry around people. But, Roy says, "we need to walk before we can run, so we're starting small."
The biggest hurdle to building a WEAV large enough to carry passengers would be making the craft light, yet powerful enough to lift its cargo and energy source. Roy is not sure what kind of energy source he will use yet. He anticipates that the craft's body will be made from a material that is an insulator such as ceramic, which is light and a good conductor of electricity. "In theory you probably should be able to scale it up," says Anthony Colozza, a researcher with government contractor Analex Corporation who is stationed at NASA's Glenn Research Center in Cleveland and helped Roy draw up the original plans for powering the saucer. The choice of a power source that is powerful, yet lightweight is "probably going to be the thing that makes or breaks it."
Flying saucer (Scientific American)
UPDATE: As several commenters point out, saying that the saucer uses air as fuel, as I did in my post based on the SciAm articl, isn't really correct.
