The European Space Agency (ESA) on Thursday announced it would launch the fourth, and heaviest, in a series of hi-tech cargo vehicles to the International Space Station (ISS) on June 5. Named the Albert Einstein, the freighter will deliver 2.5 tonnes of dry cargo, ranging from food and scientific experiments to spare parts and clothing, as well as fuel, water and oxygen. The total mass of the vehicle, its contents and fuel, will come to 20.235 tonnes, \"making this spacecraft the heaviest ever lofted into orbit by an Ariane rocket,\" ESA said. The Albert Einstein is scheduled to dock with the ISS on June 15, 10 days after launch, it added. ESA has a contract to build and deliver five so-called Automated Transfer Vehicles (ATVs) as part of its contribution to the ISS. The robot craft, each the size of a double-decker bus, are designed to make one-way trips. They are launched by an Ariane 5 heavy rocket from ESA\'s base in Kourou, French Guiana. After detaching from the launcher, the ATVs navigate their way to the orbital outpost by starlight and dock automatically. They provide stores for the ISS crew and additional living space for the duration of their mission. The ATVs also use on-board engines to boost the ISS, whose altitude drops because it is in low orbit and dragged by lingering atmospheric molecules. At the end of their trip, filled with garbage and human waste, the craft detach and burn up in a controlled destruction over the South Pacific. The fifth and last ATV, named after Belgian physicist Georges Lemaitre, the father of the \"Big Bang\" theory, is due to be launched in 2014.