By Jonathan Amos
Science reporter, BBC News
The European Space Agency is about to look in detail at how it might upgrade its space station freighter so it can return cargo safely to Earth.
At the moment, the Automated Transfer Vehicle is discarded after delivering supplies to the orbiting platform.
The agency will ask industry in the coming weeks to define the requirements for a far more capable ship.
To be known as the Advanced Re-entry Vehicle (ARV), it could be the first step to an eventual manned vehicle.
A near one-for-one mock-up of what a crewed version of this vessel might look like has been a star turn over the past week at the Paris air show.
Currently, all European astronauts must hitch a ride on Russian or American launch systems if they want to get into orbit.
Europe would like its own independent system - but only if it is affordable, feasible, and there is a genuine need for it.
The Automated Transfer Vehicle (ATV), which made such an impressive debut at the space station last year, is seen as the starting point in all these discussions.
The robotic truck has the ability to find its own way across space and then make a precise, automatic docking at its destination.
What it cannot do is bring down intact to the surface of the planet any portion of its own structure, let alone any cargo.
The maiden ATV ended its re-supply mission to the space station by plunging into the Pacific in a ball of flames.
The 18-month ARV study will set out the technical and cost implications of altering the ATV to make its cargo carrier section fit for re-entry.
EADS Astrium, which will lead a consortium of companies on the project, envisages a conical 4.4m-wide module that would separate from its propulsion unit just prior to its race through the atmosphere.
While the propulsion, or service, unit would burn up, the cargo module would be equipped with all the systems necessary to make a secure splash-down.
"The two key technologies for this cargo vehicle are the re-entry technologies - high speed entry and thermal protection systems; and also the descent and landing capability - the capability to land under parachute," said Philippe Berthe, head of advanced projects, at Astrium.
In two steps
The upload capacity (station experiments, equipment, etc) of the cargo ship would be two tonnes; the download capacity would be about one-and-a-half tonnes.
The upcoming 14m-euro study, though, will have an eye on something much grander.
While Esa is thinking in the first instance only of producing an unmanned cargo-return module, it wants engineers to think about how they could quickly and easily upgrade the vehicle's systems to support four seated humans as well.
It is a clever two-stage approach in which the flights of the cargo vessel contribute to the qualification of a later crew version - if European states want to go that far.
"The reason why we are studying the manned version of the capsule is not because we are necessarily going to approve it - we may not; but what we are trying to do is develop the cargo version already in line with what could eventually become the human version," explained the European Space Agency's (Esa) director of human spaceflight, Simonetta Di Pippo.
"In this way, we would not waste time and money if - as I hope - the manned version is eventually approved," she told BBC News.