‘Impossible’ space drives claimed to work without propellant (FT201:14) have buzzed around space science for many years like an irritatingly persistent pest. And now, that pest may be getting ready to sting – or vanish.
Such drives annoy scientists because, in the scientists’ view, they have to be hoaxes or bad science: you cannot pull yourself into the air by pulling on your own bootstraps. But in 2002 British inventor Roger Shawyer claimed effectively to have done that with his EmDrive. By confining microwaves in a truncated cone, he claimed to get more pressure on one end
