Aleph Null
02-11-2005, 11:40 AM
http://news.bbc.co.uk/2/hi/science/nature/4256907.stm
Last Updated: Friday, 11 February, 2005, 14:28 GMT
Expectations ride on super-rocket
Ariane 5-ECA rocket on the launch pad (Image: Esa) - The ECA can lift a lot more into space, cutting launch costsThe satellite industry will hold its breath on Saturday as Europe tries for the second time to fly its super-rocket - the "10-tonne" Ariane 5-ECA.
The 50m-high (160ft) vehicle exploded four minutes into its first mission in 2002, dumping a telecoms payload valued at $64m (£30m) into the Atlantic.
Rocket operator Arianespace believes it has fixed the cause of the failure and is betting its future on the ECA.
The vehicle is set to become Europe's primary launcher in the decade ahead.
Lift-off from the Kourou spaceport in French Guiana is timed for a launch window that runs from 1949 to 2110GMT.
The ECA will carry two satellites: the Spanish XTAR-EUR military communications payload and an experimental spacecraft, called SloshSat, which will study how fluids behave in orbit.
Equipment to monitor and report back on the performance of the launch will also take the ride into space. The total payload mass comes to more than 8.3 tonnes.
This is a little shy of the designed capacity of the ECA which should be capable of putting 10-tonnes into a geostationary transfer orbit.
More thrust
Arianespace does not expect single spacecraft of this mass to be regular passengers in the future; rather multiple payloads will book launches on the vehicle, substantially reducing costs for satellite owners.
http://newsimg.bbc.co.uk/media/images/40479000/gif/_40479591_arianne5_416.gif
The European rocket company already controls one half of the commercial launch sector and a successful ECA flight will further strengthen its position.
"Ariane 5-ECA will be the workhorse of our company, and of the European space industry as well, for the next 10 years," Arianespace's chief Jean Yves Le-Gall told the BBC's World Business Report.
"So this launch is very important."
He added: "We are now on a level playing field with our competitors, which are mainly US companies."
Another failure, though, and confidence will be shaken in an industry that has endured a difficult downturn in recent years and which has only just begun to look towards a brighter business future.
The Ariane 5-ECA is an altogether more powerful launch vehicle than its predecessor - the Ariane 5-Generic.
Sloshsat will help scientists study how fluid behaves in microgravityIts two solid boosters carry more propellant and there is more thrust from a new cryogenic upper stage.
But it is in the latest version of the Vulcain engine on the main cryogenic stage that the ECA gets most of its improved performance - 20% more thrust.
However, this was the part of the new launcher that failed two years ago on the maiden flight. The inquiry board that looked into the accident identified the probable cause as a leak in the Vulcain nozzle's cooling circuit.
This caused the nozzle to deform and sent the ECA off course; a self-destruct mechanism brought the rocket down far out at sea.
Modifications have since been made to the nozzle design and stringent testing suggests there should be no repeat of the problem on Saturday.
At lift-off, it is calculated that the 780-tonne ECA will be producing 13,000 kiloNewtons of thrust, and at maximum velocity, some 640km above the Earth, its upper stage will be travelling at more than 9km/s.
Although impressive, these figures do not match those of the recently launched Boeing Delta 4-Heavy, which has the capability to put 13 tonnes of payload into a geostationary transfer orbit.
However, the Boeing vehicle is not currently being offered to the commercial satellite sector and is being reserved for US military work.
Last Updated: Friday, 11 February, 2005, 14:28 GMT
Expectations ride on super-rocket
Ariane 5-ECA rocket on the launch pad (Image: Esa) - The ECA can lift a lot more into space, cutting launch costsThe satellite industry will hold its breath on Saturday as Europe tries for the second time to fly its super-rocket - the "10-tonne" Ariane 5-ECA.
The 50m-high (160ft) vehicle exploded four minutes into its first mission in 2002, dumping a telecoms payload valued at $64m (£30m) into the Atlantic.
Rocket operator Arianespace believes it has fixed the cause of the failure and is betting its future on the ECA.
The vehicle is set to become Europe's primary launcher in the decade ahead.
Lift-off from the Kourou spaceport in French Guiana is timed for a launch window that runs from 1949 to 2110GMT.
The ECA will carry two satellites: the Spanish XTAR-EUR military communications payload and an experimental spacecraft, called SloshSat, which will study how fluids behave in orbit.
Equipment to monitor and report back on the performance of the launch will also take the ride into space. The total payload mass comes to more than 8.3 tonnes.
This is a little shy of the designed capacity of the ECA which should be capable of putting 10-tonnes into a geostationary transfer orbit.
More thrust
Arianespace does not expect single spacecraft of this mass to be regular passengers in the future; rather multiple payloads will book launches on the vehicle, substantially reducing costs for satellite owners.
http://newsimg.bbc.co.uk/media/images/40479000/gif/_40479591_arianne5_416.gif
The European rocket company already controls one half of the commercial launch sector and a successful ECA flight will further strengthen its position.
"Ariane 5-ECA will be the workhorse of our company, and of the European space industry as well, for the next 10 years," Arianespace's chief Jean Yves Le-Gall told the BBC's World Business Report.
"So this launch is very important."
He added: "We are now on a level playing field with our competitors, which are mainly US companies."
Another failure, though, and confidence will be shaken in an industry that has endured a difficult downturn in recent years and which has only just begun to look towards a brighter business future.
The Ariane 5-ECA is an altogether more powerful launch vehicle than its predecessor - the Ariane 5-Generic.
Sloshsat will help scientists study how fluid behaves in microgravityIts two solid boosters carry more propellant and there is more thrust from a new cryogenic upper stage.
But it is in the latest version of the Vulcain engine on the main cryogenic stage that the ECA gets most of its improved performance - 20% more thrust.
However, this was the part of the new launcher that failed two years ago on the maiden flight. The inquiry board that looked into the accident identified the probable cause as a leak in the Vulcain nozzle's cooling circuit.
This caused the nozzle to deform and sent the ECA off course; a self-destruct mechanism brought the rocket down far out at sea.
Modifications have since been made to the nozzle design and stringent testing suggests there should be no repeat of the problem on Saturday.
At lift-off, it is calculated that the 780-tonne ECA will be producing 13,000 kiloNewtons of thrust, and at maximum velocity, some 640km above the Earth, its upper stage will be travelling at more than 9km/s.
Although impressive, these figures do not match those of the recently launched Boeing Delta 4-Heavy, which has the capability to put 13 tonnes of payload into a geostationary transfer orbit.
However, the Boeing vehicle is not currently being offered to the commercial satellite sector and is being reserved for US military work.