Experts are investigating whether plans for a European navigation system to rival the US-developed GPS are in trouble after two satellites were launched into the wrong orbits.
The European Space Agency (ESA) said the satellites ended up in the wrong position above the Earth after being carried into space on a Soyuz rocket on Friday. The ESA did not clarify whether the problem could be fixed.
However, the Nasa Spaceflight news website said: "It is unlikely the satellites can be eased into their correct orbit."
The satellites were launched from Kourou, in French Guiana, by the agency and Arianespace, a French company.
The European Union's 30-satellite Galileo navigation network is due to be up and running before 2020. It has a budget of £7bn and so far, six satellites have been launched.
Galileo would rival GPS, or Global Positioning System, which was created by the US Department of Defense and has been operational for nearly 20 years.