It may sound like something that would transport the Heart Of Gold in The Hitchhiker's Guide To The Galaxy, but the "impossible drive" may soon be racing our explorers to Mars and powering our satellites. More formally known as the "electromagnetic drive," or "emdrive" for short, this steampunk-looking device converts electrical energy into thrust via microwaves, in a way that some physicists believe is impossible. But the Chinese claim they're building a prototype right now. British scientist Roger Shayer caused a stir when New Scientist highlighted his claims that an em drive could violate strict Newtonian physics, thanks to an effect of Einsteinian relativity. The drive works by filling a "tapering resonant cavity" with microwaves. Critics have dismissed Shayer's idea as another perpetual motion machine, and the British government cut off his funding. But his assocation with China's Northwestern Polytechnical University in Xi'an paid off, and the NPU team has been able to confirm Shayer's work independently. They also claim they're building a a thruster based on Shayer's theories. If it works the emdrive could create almost as much thrust as the ion thruster NASA currently uses, but using a quarter of the power, Shayer tells Wired. Says Wired:

The possibilities are phenomenal: Instead of going out of service when they run out of fuel, satellites would have greatly extended endurance and be able to move around at will. (We wouldn't have to shoot them down because of the risk from toxic fuel either.) Deep space probes could go further, faster –- and stop when they arrive. Shawyer calculates that a solar-powered Emdrive could take a manned mission to Mars in 41 days. Provided it works, of course.

If this actually pans out, and the Chinese government reaps the benefits, it'll be an object lesson in the dangers of dismissing new scientific ideas out of hand. It could have been Britain building the next-generation fleet of super-fast Mars explorers, after all. Mostly, though, a Chinese breakthrough in the "impossible drive" could spark a new space race — especially if, as Wired hints, the emdrive stands to give China a decisive military advantage in space. [Wired]