A meeting of ministers of the European Space Agency's 20 member states in Italy this week will consider a proposal to join in the construction of the four-person U.S. Orion space capsule.
"Europeans will have the power to put men and women into space," Jean-Jacques Dordain, director general of the European Space Agency, told Britain's The Observer newspaper in an interview. "That would be a fantastic development for us."
"Britain has already indicated support," he said.
One candidate astronaut is Britain's Tim Peake, selected three years ago for European astronaut training.
While Peake's best chance of space flight would be a mission to the International Space Station, he and his European astronaut colleagues could have the opportunity of a deep space flight if Europe joins the Orion program.
The Orion capsule, intended to carry astronauts on missions of up to six months, could take crews to the moon, an asteroid or possibly even eventually to Mars.
No single nation can now afford to conduct a program of manned space exploration on its own, Dordain said.
"There is not a single space power left in the world that thinks they can afford to send men and women to explore the moon or Mars on their own national budget," he said. "This is something that will have to be done by international co-operation."