DEFUNCT global positioning satellites are being junked in graveyard orbits in which they risk colliding with their active sister satellites, according to research commissioned by the US Air Force. The errant spacecraft could pose a threat to the Global Positioning System in decades to come, as well as other satellites in low-Earth and geostationary orbits.
Engineers say the risk of a collision between dead and active GPS satellites is increasing all the time. And even without a collision, the service is in jeopardy as a dead satellite that drifts within a few hundred metres of an active satellite might obstruct…
