We did not reach the desired orbit - we apologise to our clients

Jean-Marie Luton, Arianespace

European Space Agency (Esa) experts said there was a possibility the satellites could be salvaged, but that firing their reignitable engines could shorten their lifespan.

The Artemis satellite has two engines, while the Japanese Bsat-2B television orbiter has only one.

Full apology

Arianespace President Luton apologised to clients for the failure to reach proper orbit.

The $850m Artemis satellite was partially insured. Bsat-2B officials were not available to comment.

The satellite was meant to orbit 36,000 km above the Earth

The Ariane programme, which began in 1979, has a good record. Only eight of its 141 missions have ended in failure - the most spectacular being the Ariane 5's maiden test-flight in 1996. The vehicle was destroyed 37 seconds after launch as it veered off course.

The latest failure is considered unlikely to affect Ariane's full order book.

Thursday launch from Europe's space port in Kourou, French Guiana, went well at first.

The Artemis payload was aiming for a final geostationary orbit at 21.5 degrees East over central Africa, about 36,000km (22,300 miles) above the ground. At present, its orbit is only reaching a maximum of 17,500km (10,940 miles).

Most advanced

Artemis is the most advanced telecommunications satellite yet developed by Esa and its partners. It will act as a demonstrator for new technologies.

Artemis is a demonstrator for future space technologies

The multi-purpose satellite is designed to conduct trials of Europe's proposed satellite navigation system, which Esa claims will be more accurate and more reliable than the American Global Positioning System.

It is also meant to demonstrate new mobile communication technologies that should eventually make telephone conversations possible via satellite anywhere in Europe, North Africa or the Near East - even at sea.

Its system of propulsion, which uses ionised xenon as the propellant, should make future satellites more compact.

It is also intended to test direct satellite-to-satellite communications, including a revolutionary laser link that is so accurate the light pulses can hit a target the size of a coin at 10km (six miles). The link is expected to replace conventional earthbound relay systems, and should dramatically improve the time it takes for satellites to pass data between each other and their terrestrial base stations.

Earth observation satellites should send down their pictures of the planet much faster, for example.