The solar sail isn’t a new idea, especially not to anyone well read in science fiction. But even old ideas can be improved upon – like this new twist on the solar sail concept by a group of Finnish engineers that will make them cheaper, more efficient, and faster. And if you think that it sounds too complex to work, bear in mind we’ve already got satellites that can repair themselves and others. Many things are just within our grasp, if only we’d bother to reach.