Facebook has bought a Somerset-based designer of solar-powered dronesfor $20m (£12m) as it goes head-to-head with Google in a high-altitude race to connect the world's most remote locations to the internet. Mark Zuckerberg, Facebook's chief executive, has unveiled plans to beam broadband connections from the skies, using satellites, lasers and unmanned high-altitude aircraft designed by the 51-year old British engineer Andrew Cox.