Those support payments, plus the €3.8-5 billion cost estimate for development, means Ariane 6 will cost a minimum of €5 billion over 10 years. Continuing development of Ariane 5ME, in which Europe has already invested around €300 million, would cost €1.4 billion over five years, when an operational vehicle comes on line in 2018, putting the total cost at €2 billion.

Woerner says a recent letter to ESA from Ariane 5 prime contractor Astrium, the space division of EADS, suggests that once Ariane 5ME is operational, Arianespace will no longer need European price supports. Ariane 5ME is designed to offer a 20% boost in carrying capacity over Ariane 5. It is also more palatable in terms of environmental impacts, as its restartable upper stage is designed to be destroyed post-launch as it reenters Earth's atmosphere. Multiple conditions in the letter suggest industry participation is necessary for this to occur, but so long as the market remains nominal during the anticipated five-year development period, Astrium says it is doable.

But for Ariane 6, it is impossible to guarantee that ESA subsidies can be eliminated, Woerner argues.

Officials at the French space agency CNES declined to comment on the Franco-German launch vehicle report, but Michel Eymard, director of launchers at CNES, says France's interest in moving quickly ahead with Ariane 6 is driven by the need to end annual support payments to Arianespace while reducing the company's reliance on commercial business.

“In France, our objective is to keep a reliable system, an available system, but also a system which does not require any support from the public sector during the exploitation phase,” Eymard said at a May conference on space propulsion in Bordeaux. “The requirement for Ariane 6 is to have a balanced exploitation,” even if competition in the launch market escalates.

Woerner, however, says Germany's position is that Europe should be less concerned with building vehicles that will survive despite an uncertain commercial market and more with sustaining a consistent industrial policy that supports a highly skilled engineering workforce that can keep Europe on the leading edge of space.

“We are not producing launchers for the market, we are producing launchers for European access to space,” Woerner says. “The market is an interesting point but not the overall one governing the debate.”

With France's new government expected to unveil a new space policy by late summer, French Minister of Research and Higher Education Genevieve Fioraso says maintaining Europe's independent access to space is a key element of the forthcoming strategy.

“The space policy that we are backing must affirm independence as one of its major strategic objectives,” Fioraso said in June during the Toulouse Space Show, adding that “it is an absolute necessity for Europe to maintain its independent access to space.”