Fourth flight for biggest Ariane

Europe's most powerful rocket - the Ariane 5-ECA - has launched two
satellites from French Guiana.

It lifted off from Kourou spaceport at 1932 local time (2232 GMT),
carrying satellites for the Spanish defence ministry and a French
telecoms company.

The launch marked the Ariane 5's first flight this year and only the
fourth for the 780-tonne heavy-lift version.

The ECA has the power to push 10,000kg of payload towards geostationary
orbit, 36,000km above the Earth.

The mission had originally been scheduled for 21 February but was put
off three times because of technical problems with ground support
equipment, the payload and the upper stage of the launcher.

Saturday's attempt, however, proceeded without a hitch.

The first satellite released, 27 minutes into the flight, was the
3.7-tonne Spainsat, the first Spanish satellite dedicated to secure
government communications.

It shared a ride with the 4.1-tonne Hot Bird 7A, the 21st satellite
launched for the Paris-based telecoms operator Eutelsat Communications.

Eutelsat Communications said Hot Bird 7A would transmit more than 850
television channels and 550 radio stations to 110 million homes in
Europe, North Africa and the Middle East for the next 15 years.

Saturday's launch was the 170th of an Ariane rocket since the start of
the French-led programme in 1979.

The generic Ariane 5 launcher went into full commercial service in
1999, and was followed a few years later by the beefed-up heavy-payload
version.

The first Ariane 5-ECA had to be destroyed on its maiden flight in 2002
but flew successfully twice in 2005.

It has two solid boosters to lift it off the ground, 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, or geostationary transfer
orbit.

From this altitude, the spacecraft use their own onboard propulsion
systems to move into final parking positions high above the planet.

To get the extra performance, the ECA's 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 compared with the generic vehicle, however, is the
introduction of a new upper stage based on tried and tested
technologies used on the much older, but now retired, Ariane 4
launcher.

http://news.bbc.co.uk/1/hi/sci/tech/4737186.stm

I'm seriously impressed as all get-out; GSO at 78:1
Fourth flight for biggest Ariane
Europe's most powerful rocket - the Ariane 5-ECA - has launched two
satellites from French Guiana.

It lifted off from Kourou spaceport at 1932 local time (2232 GMT),
carrying satellites for the Spanish defence ministry and a French
telecoms company.

The launch marked the Ariane 5's first flight this year and only the
fourth for the 780-tonne heavy-lift version.

The ECA has the power to push 10,000kg of payload towards geostationary
orbit, 36,000km above the Earth.
-
To get the extra performance, the ECA's 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 compared with the generic vehicle, however, is the
introduction of a new upper stage based on tried and tested
technologies used on the much older, but now retired, Ariane 4
launcher.

Stephen Horgan,
How much tonnage to LL-1 if that task were given 29.5 days of taking
the fullest advantage of the sun and moon gravity?
-
Brad Guth