BERLIN — French space minister Genevieve Fioraso, in an apparent overture to Germany, on May 20 said France is willing to entertain modifications to the design of the next-generation Ariane 6 rocket so long as the changes stick to the established credibility criteria and are in hand by July 8.

Fioraso, who had her third meeting with her German counterpart, Brigitte Zypries, here May 19 in the run-up to the ILA Berlin Air Show, said space ministers from Germany, France, Italy, Switzerland and perhaps elsewhere are scheduled to meet July 8 in Geneva to review Ariane 6’s design.

Ministers from the 20-nation European Space Agency are scheduled to meet in Luxembourg in December to make a final decision on what direction Europe’s launcher sector will take.

On the table is a mainly solid-fueled Ariane 6, which with a new launch pad and related ground infrastructure is estimated to cost 4 billion euros ($5.5 billion) over seven years; an upgrade of the current Ariane 5 heavy-lift rocket, with a price tag of 1.2 billion euros; and enhancements for Europe’s new Vega small-satellite launcher.

Ariane 6 Design Offers Economies of Scale

One European industry official said that in launch vehicles alone, the total package is not far from 10 billion euros over 10 years.

The ministers are also scheduled to give final approval for Europe’s continued participation in the U.S.-led international space station to 2020.

France is expected to finance 50 percent of the Ariane 6 development, 50 percent of the Ariane 5 upgrade, and a minority stake in the Vega enhancements — in addition to paying for the space station program as Europe’s second-largest contributor after Germany.

German government officials have said they will have difficulty supporting the current Ariane 6 design, which features four identical solid-fueled stages — two as strap-on boosters, and two as the vehicle’s first and second stages — topped by  the cryogenic upper stage powered by the same restartable Vinci engine that is the main element of the proposed Ariane 5 upgrade.

Germany, through its space agency, the German Aerospace Center, DLR, has said it would prefer a liquid-fueled first stage for Ariane 6 as such a stage could be built in Germany and thus assure a large German industrial role in the program. Without such a role, DLR has said, German support for Ariane 6 might not be forthcoming.

Noting the continued differences between Germany and France, Fioraso said industry is free to propose modifications to the Ariane 6 design if the alterations respect the criteria that led to the current design.

She also said that, to make the launcher package more financially palatable to France, the proposed in-service date of Ariane 6 could be changed. Currently the vehicle is scheduled to make a demonstration flight in 2021, assuming it receives full funding go-ahead in December.

Fioraso’s comments here came a day after the continued gulf between German and French opinion was made evident at the Space Propulsion 2014 conference in Cologne, Germany, organized by the French 3AF organization.

Jean-Yves Le Gall, president of the French space agency, CNES, said the Ariane 6 design using four identical solid-fueled stages has unbeatable economies of scale as well as the reliability record in Europe that liquid propulsion cannot match.

Current Ariane 6 business-case models are based on the vehicle replacing both the heavy-lift Ariane 5 and the medium-lift Soyuz — a Europeanized version of Russia’s venerable rocket now operated from Europe’s spaceport — by around 2025.

Once the transition has been accomplished, Ariane 6 could be expected to fly around 12 times per year, meaning an annual production run of 48 solid-rocket stages.

Herve Austruy, general director of Herakles, the solid-rocket propulsion unit of France’s Snecma rocket-motor builder, told the conference that the scale economies of building so many identical stages are much better at a 48-unit production rate than at a 36-unit rate — at least 20 percent if not more, he said.

DLR representatives at the conference said the debate about Ariane 6 was a good thing and could not be reduced to which version offers the greater economies of scale.

Johann-Dietrich Woerner, chairman of DLR, said it is healthy that with so much taxpayer money at stake, “we have an intensive discussion. This is Europe, we do not need to put just one idea on the table and then accept it.”

Claus Lippert, DLR’s launcher director, was asked whether a liquid-fueled first stage on Ariane 6 would upset the vehicle’s principal cost goal of 70 million euros, including launch.

“Germany is willing to take the necessary measures to secure Europe’s liquid propulsion competence,” Lippert said. “And we have a strong commitment to maintain the Lampoldshausen [Germany] test site. We are pursuing the option of a liquid-powered Ariane 6 as a backup solution for Ariane 6. We are not sure the current version can succeed.”

Lippert said Ariane 6’s success depends on more than just volume-based cost reductions. The needed restructuring of Europe’s rocket industry is part of the program, and this, he suggested, could not occur if Germany does not have a large role in Ariane 6.


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Peter B. de Selding was the Paris Bureau Chief for SpaceNews.