Earlier this autumn, Russian billionaire Yuri Milner casually announced his intention to develop spacecraft that can travel at up to 20 per cent the speed of light and reach Alpha Centauri within 20 years. From the outset, it was clear that no humans would be making the warp jump -- the mission will involve extremely lightweight robotic spacecraft. A new fleet of tiny satellites hints at what those future interstellar voyagers will look like and be capable of.