Spaceships could use blinking dead stars to chart their way

Like GPS satellites, pulsars could help ships pinpoint their place in space

illustration of SEXTANT

SPACE PLACE  NASA’s SEXTANT experiment demonstrated a stellar version of GPS, finding the experiment’s location with an apparatus consisting of 52 X-ray telescopes (illustrated) on the International Space Station.

NASA's Goddard Space Flight Center

OXON HILL, Md.