By Jonathan Amos
Science reporter, BBC News
More details are expected at the Berlin Air Show
A plan for a manned spacecraft has been announced by the European firm EADS.
Its Astrium division has designed a variant of its space station freighter that could also transport astronauts.
Limited details were released in Bremen, Germany, on Tuesday; further information and a mock-up are expected at the Berlin Air Show this month.
Europe does not currently possess its own human space transportation system and is reliant on the Americans and the Russians to get its people into orbit.
European Space Agency (Esa) boss Jean-Jacques Dordain has spoken frequently of his desire to see an independent system; and the US space agency (Nasa) chief, Mike Griffin, has also urged Europe to build its own crew carrier.
The concept leans heavily on ATV technology
Now, EADS Astrium and the German Space Agency (DLR) have put ideas forward on how this could be achieved by as early as 2017.
They propose to adapt the technology contained in Europe's new space station freighter, known as the Automated Transfer Vehicle, to make a crew ship capable of carrying three people.
The ATV, which ferried just under five tonnes of supplies to the orbiting platform in April, is packed with sophisticated navigation, rendezvous and docking technologies.
It also has a pressurised section that is "human rated" in the sense that, once docked to the 340km-high station, astronauts can move around inside it safely in just T-shirts.
But the ATV was not built with the intention of transporting humans across space, and a fit-for-purpose capsule would have to be developed to take the place of the current cargo section.
In addition, the freighter is a use-once-and-throw-away vehicle - it has no capacity to re-enter the Earth's atmosphere intact. Heat-shield technology would therefore also need to be developed for the capsule, to help it survive the immense temperatures experienced when falling to Earth.
Esa once considered having its own shuttle, called Hermes
Astrium senior executive Evert Dudok and DLR boss Johann-Dietrich Worner told German journalists that the concept could be realised without spending billions of euros.
They envisage a version ready for unmanned testing by 2013, with the first manned flight four or five years later.
The current ATV is launched atop an Ariane 5, the rocket which at one stage was going to loft Europe's mini-shuttle known as Hermes until the spaceship project was cancelled in the 1990s.
The concept announced on Tuesday has not yet been put formally to European partners who would need to support the venture if it were to proceed under the aegis of Esa.
The next meeting of European space ministers, when such major decisions are taken, will take place in November in The Hague.