ESA Ariane 5 - 'Johannes Kepler' space freighter ready for launch

Europe's unmanned space freighter is on the launch pad in French Guiana, ready to begin its voyage into orbit.

At more than 20 tonnes, the truck will be the heaviest payload an Ariane 5 rocket has ever lifted into the sky.

The robotic ship, dubbed Johannes Kepler, will be delivering food, air, fuel, experiments and other equipment to the International Space Station.

Another key task for the freighter in the coming months will be to push the station to a higher altitude.

The ISS has a tendency to lose height over time as it brushes through the residual atmosphere still present 350km above the Earth.

Johannes Kepler will dock with the rear of the platform and use its propulsive might to boost the station's orbit.

Lift-off for the freighter and its carrier Ariane from the Kourou spaceport is timed for 1913 local time (2213 GMT) on Tuesday.

The launch is doubly significant because it marks also the 200th mission of an Ariane rocket since the vehicle series was introduced in 1979.

"Kepler's mass at lift off will be 20,062kg. This is a record for the launcher and for the European Space Agency (Esa)," said Nico Dettmann, who runs the freighter programme at Esa.

"The integration and launch campaign have been very smooth, but still we have to be thorough and careful," he told BBC News.



An artist's impression of ATV2 Johannes Kepler flying over France

Kepler is due to make a docking with the orbiting platform next Wednesday.