Europe's last supply vessel to the International Space Station undocked on Saturday at the end of a six-month mission, the European Space Agency (ESA) said.

The automated spaceship, the Georges Lemaitre, separated from the ISS ahead of an operation on Sunday to burn it up in Earth's atmosphere, ESA said.

It is the last of five so-called Automated Transfer Vehicles (ATV) that ESA has contracted to provide for the US-led ISS project.

Each the size of a double-decker bus, the ships are designed to haul fuel, water, experiments and other essentials to the ISS crew.

After launch, they navigate their way by starlight and dock automatically -- technologies that are to be used in future US space missions.

During their mission, the pressurised units are used for storage and for living space, and are filled with human waste and rubbish before they are destroyed by re-entry.

Sunday's suicide plunge is scheduled for 1812 GMT.

It had initially been set for February 27 to enable flight engineers to test a trajectory that could help planning for the ISS's own destruction in the future.

But that plan was scrapped when a fault developed in one of the ATV's four power sources.

The problem is minor but re-entry was brought forward as a precaution, said mission officials.

Power hiccup to speed end of Europe's space truck
Paris (AFP) Feb 13, 2015 - A European supply ship will undock from the International Space Station on Saturday as scheduled but be destroyed 12 days earlier than planned because of a power hitch, the European Space Agency (ESA) said Friday.

The Automated Transfer Vehicle (ATV) Georges Lemaitre will separate from the ISS on Saturday at 1344 GMT at the end of its six-month mission, it said.

But the loss of one of its four power sources means that, as a precaution, the ATV will be destroyed on Sunday rather than on February 27 as initially planned.

"It's a minor concern rather than a critical problem," Dominique Siruguet, deputy head of ESA's ATV programme, told AFP.

"The ATV has four solar panels," he said.

"It can operate as normal using three power chains, but even if this were reduced to two, it would still be able to separate from the ISS and perform re-entry satisfactorily."

Re-entry entails sending the vehicle earthward at a steep angle so that it burns up on friction with the atmosphere at hypersonic speeds.

The ATV is the fifth and final cargo ship that ESA contracted to provide for the US-led ISS project.

Named after the father of the "Big Bang" theory, the spaceship is designed to navigate by starlight and dock automatically with the manned outpost in space.

The 10-metre (32.5-feet) -long ATV was launched by an Ariane 5 rocket in August, bringing 6.6 tonnes of fuel, water, oxygen, food, clothes and scientific experiments for the six ISS crew.

The initial plan was to use the ATV's death plunge as an experiment to provide data for the ISS's own demise, which is sketched for around 2024.

The idea was to see whether a longer, shallower angle of re-entry would help to burn up the ISS, which has a mass of around 420 tonnes (925,000 pounds).

The experiment has been scrapped and a conventional re-entry operation will now take place, ESA said.

It is scheduled for Sunday at around 1812 GMT, ESA said on its website.