The lead spacecraft in Europe's new multi-billion-euro Earth observation (EO) programme is built and ready to go into orbit. Sentinel-2a will take pictures of the planet's surface in visible and infrared light. Its data will track everything from the growth of megacities to the variable yields of the world's most important food crops. The satellite will ship to the Kourou spaceport in the next month. Its launch on a Vega rocket has been scheduled for 12 June.