A navigation satellite sent astray by a mislaunch in August, has sent a signal from its faulty orbit, and may yet prove useful, the European Space Agency (ESA) said Tuesday.

Didier Faivre, head of ESA's Galileo satnav programme, a rival to America's GPS, said the "first signals" from the orbiting constellation's fifth satellite were received on Saturday after it managed to manoeuvre into a slightly better position.

"We are now in a safe place and we can work and we still have the hope that this satellite could be used for the navigation receivers," Faivre told an ESA ministerial meeting in Luxembourg.

"We rescue what we can rescue," he added.

On August 22, Galileo satellites Sat-5 and Sat-6 were placed in the wrong orbit by a Soyuz rocket launched from Europe's space base at Kourou in French Guiana.

They should have been slotted into a circular orbit at an altitude of 23,500 kilometres (14,600 miles), inclined at 56 degrees to the equator.

Instead, they were placed in an elliptical orbit at a height of 17,000 kilometres -- a position many experts said made them useless for satnav work.

But Faivre said Sat-5 managed to manoeuvre into a new position and its twin would attempt to do the same in the coming days.

The August 22 hitch has been blamed on frozen fuel pipes aboard the launcher's fourth stage, called Fregat.

Europe's seven-billion-euro (8.9-billion-euro) Galileo project has encountered a long series of technical hitches and budget questions.

By 2017, according to the Galileo schedule, all 24 operational satellites should be in place. Six backups would join the fleet by 2020, at which point the system would be fully operational.