Math leads spacecraft on joy rides through the solar system
Last April, the Genesis spacecraft began its journey home. It had been parked out in space collecting solar particles for 2 years. Yet even though its job was done, Genesis didn't head straight home. Instead, it took a 3-million-mile detour, swinging past Earth to do a loop de loop around a distant point before flying back to Earth.
This circuitous route was no accident. The spacecraft had hopped aboard the interplanetary superhighway, a network of tubes crisscrossing through the solar system. By jumping from one tube to another at the solar syste