"Scientists are increasingly worried about the amount of debris orbiting the Earth." The Economist says the number of potential collisions among space satellites has doubled in the last decade. The speeds at which satellites travel in Low Earth Orbit—about eleven miles per second—make even small pieces of junk big enough to knock out important space equipment, whether they be for civilian mobile communication or military satellites. And a further problem: "junk begets junk" says The Economist, following the American physicist Donald Kessler. When one satellite is destroyed and splits into thousands of small pieces, each piece is another potential satellite killer, and so on...