Super rocket to try again

A new date has been set for the super rocket

Europe will have a second go at launching its new super rocket on Wednesday.

The Ariane 5-ECA is capable of lifting 10 tonnes of payload towards geostationary orbit.

The vehicle's maiden flight - with two satellites on board - was aborted on 28 November just 13 seconds before it was due to lift clear of the launch pad at Kourou in French Guiana.

A technical problem associated with the rocket's main Vulcain 2 engine was responsible.

The system used to clear the hydrogen that chills the engine just prior to blast-off failed to send a message to launch computers indicating all was working properly.

The countdown was automatically halted as a result.

"The launch countdown interruption was a textbook operation," said Jean-Charles Vincent, head of operations at the Kourou spaceport for the rocket's operators, Arianespace.

"It was handled just as we had practised for such situations, with the Ariane 5 and its two satellites immediately reconfigured to the safe mode."

The launcher was taken back to its assembly shed for checks and the faulty parts exchanged.

Fewer customers

The vehicle, the latest variant in the highly successful Ariane series, is the most powerful rocket ever built by Europe.

It will operate at the top end of the very competitive, but currently depressed, launcher market.

The rocket was taken back to the assembly shed for checks

The Ariane 5-ECA will go head-to-head for business with Lockheed Martin's Atlas 5 and Boeing's Delta 4, both of which have debuted within the last few months.

But whereas the two US rockets will benefit from a steady stream of orders from the American military, the Ariane will be dependent largely on commercial customers.

During the 1990s, these clients were demanding vehicles capable of launching ever heavier geostationary telecommunications satellites - from 2.5 to five tonnes.

Then, towards the end of the decade, the market turned down and although the size of satellites has continued to increase, there are fewer of them to place in orbit.

Better performance

Nonetheless, Arianespace, which operates Europe's rockets for its member states, hopes the bigger launcher will find success.

Because the 10-tonne can deliver into orbit two different satellites at once, it can keep costs down.

It has to work in a tough market

Wednesday's event will be just such a dual launch. The Ariane 5 is loaded with a Hotbird TM7 satellite, for the European telecoms consortium Eutelsat, and Stentor, an experimental communications satellite for the French space research institute CNES.

The new rocket is a development of the generic Ariane 5 launcher that went into full commercial service in 1999.

It has two solid boosters to lift it off the launch pad, a cryogenic main stage to do most of the work of getting into orbit, and an upper stage to place the satellites in the target orbit, in most cases a geostationary transfer orbit of up to 36,000 kilometres from where their onboard propulsion systems take them into their final orbits.

To get the new, beefed up performance, the solid boosters carry more propellant and the main Vulcain cryogenic engine has been modified to improve its combustion of liquid oxygen and hydrogen.

The main difference, however, is the introduction of a new upper stage (ESC-A) based on tried and tested technologies used on the much older Ariane 4 launcher.

Wednesday's launch window opens at 1922 Kourou time (2222 GMT) and continues to 2014 (2314 GMT).