Europe's super launcher put on hold

It had been anticipated that the Ariane 5-ECA (ESC-B), capable of pushing a 12-tonne payload towards a geostationary orbit, would enter service in 2006.

However, the failure of its predecessor, the "heavy-lift" Ariane 5-ECA (ESC-A), coupled with ongoing stagnation in the commercial market, has prompted European Space Agency (Esa) bosses to reconsider any further enhancements.

" It's a precautionary measure "
Franco Bonacina, Esa

The Esa has already spent large sums developing the Vinci engine to power the ESC-B since 1999.

Instead, it says it will concentrate on the reliability of its existing launchers.

Some experts have questioned the need for an even bigger rocket.

Rosetta blow

December's failure has already caused a severe delay to the Rosetta comet-chasing mission, which had been due to embark this month.

It could be as much as 30 months before the probe can be set on its way.

Franco Bonacina, at the European Space Agency, told BBC News Online: "It's a precautionary measure.

" They have to revise and consider the importance of having a vehicle like this "
Rachel Villain, Euroconsult

"Before embarking into a new version [of the Ariane 5], it's certainly wiser to ensure you can have absolute confidence in the best launcher system in the world."

However, he conceded that continuing uncertainty over the market for commercial satellite launches was another factor in the decision.

He did not rule out a return to the ESC-B in the future should the conditions improve.

Market direction

Rachel Villain, executive vice president of Euroconsult, which offers expertise on the space market, also queried whether a 12-tonne geostationary launcher was a good idea at present.

She said: "Where is the market for it?

"They have to revise and consider the importance of having a vehicle like this."

She said that the ESC-B offered a vast improvement in the payload that could be delivered into lower orbits, but that an "increase in confidence" would be needed before it could be built.

The budget for the development of the launcher was 400 million euros for the Vinci engine from 1999, and almost 700 million euros for the launcher between 2002 and 2006.

The Ariane 5's principle competitors are likely to emerge from the US, where the launcher market is healthier because of the high demand for satellite launches from the US Government.