In the late 18th Century, Captain Cook set out on a voyage of discovery clutching a pocket watch to help him keep track of his location.
The timepiece, which he described as "our faithful guide", was accurate to a couple of seconds per month, and helped fix the position of his ship to a distance of two nautical miles.
Two hundred years later, the general principle of using clocks to aid navigation still stands. But the latest generation of timepiece, to be launched into space onboard the Giove-B satellite, is a world away from Captain Cook's.
More: http://news.bbc.co.uk/2/hi/science/nature/7360762.stm
A demonstrator satellite for Europe's proposed Galileo satellite navigation system is "in good health" despite a glitch shortly after launch.
Controllers were unable to use their preferred method for turning the spacecraft and instead had to fire the thruster engines - which wastes fuel.
However, they have now been able to correct the problem by uploading a software patch to the spacecraft.
The Giove-B satellite was launched atop a Russian Soyuz rocket on 26 April.
More: http://news.bbc.co.uk/2/hi/science/nature/7375032.stm