Space for Kids

Kids (en)
Our Universe
Life in Space
Useful space
Four-satellite Galileo constellation
Four-satellite Galileo constellation

Galileo satellites get the green light

13 February 2014
Europe is confidently looking forward to having the world's first non-military satellite navigation system, now that the first four Galileo satellites passed their tests with flying colours.

The Galileo quartet was launched in 2011 and 2012 in order to prove that the complex system worked as advertised. The reason they launched four satellites is because that is the minimum number of satellites needed to accurately locate places on the Earth. Since then, they have been going through a period of tests in order to demonstrate that the system operates as planned.
On 12 March 2013, the satellites performed their first historic pinpointing of a location on the ground. Over the following months, many more navigation messages were sent during an intensive check-out of the entire Galileo system.

All of this hard work has proved that Galileo works very well. With only four satellites, it has been able to fix positions to within 8 m horizontally and 9 m vertically. Its average timing accuracy is 10 billionths of a second, and most distress signals have been pinpointed quickly to within 2 km. This performance will be even better as the full Galileo system comes on line.

Europe is now looking forward to launching the remaining satellites and deploying further ground stations. Six satellites are planned to join the existing four during 2014, so that Galileo’s operational services can start by the end of the year!

Copyright 2000 - 2014 © European Space Agency. All rights reserved.