NASA tests navigation system that lets satellites find position without GPS
NASA has tested FALCON, a system that lets satellites navigate without GPS by using other spacecraft and orbital debris as reference points. During a three-day test, the system autonomously improved the known orbits of more than 200 space objects while also calculating the position of NASA’s Starling spacecraft.
We haven't written up this one. Times of India has the full story — the link below goes straight to it.