The Automated Transfer Vehicle is the biggest spaceship ever built in Europe. Although unmanned in flight, once attached to the International Space Station astronauts can move freely around inside it. At launch, it weighs some 20 tonnes, and its primary purpose is to haul fuel, water, air, food and equipment to the space station.
Its colossal load forms the basis of the "subscription fee" Europe pays to belong to the orbiting project. But with only three more freighters set to fly beyond the vessel already attached to the international outpost, ESA thinks it imperative that Europe define a follow-on as soon as possible so that the industrial expertise gained on ATV can be maintained and developed.
ESA has the same concerns that NASA does at the end of Shuttle. It's imperative that OUR expertise is maintained and developed as well. If the next generation of the ATV can be modified to a manned vehicle, it allows for some interesting possibilities. Yet it is uncertain if there will even be a follow-on vehicle.