Advances in materials and manufacturing technology has enabled space systems to be miniaturized to unprecedentedly small sizes. As satellites shrink, the engines that propel them must shrink too. This image, taken using a scanning electron microscope, shows how even something as complex as an electric rocket engine can be made microscopic. Each of the conicals structures shown is capable of emitting ions to produce thrust and is approximately the width of a human hair. Contributors: Matthew Corrado, Paulo Lozano