The Global Positioning System works so well for cars, ships and planes that it has inspiered German scientists to develop similar system that would allow a spaceship to precisely navigate the Milky Way Galaxy. Instead od a ring of satellites this system would use X-ray signals from pulsars. Pulsars are a type of dead star whose rotation produces X-ray signals with an highly exact rhythm. The system works by combining pulsar pulse data from a reference location such as Earth allowing spaceships to determine their location in space to an accuracy of 3 miles. Even in the solar system such a system would be more accurate than current methods.