PARIS — The head of Germany’s space agency on March 19 urged European governments to scrap the current favored design for a next-generation Ariane 6 rocket, saying the vehicle could not win German financial support.

Johann-Dietrich Woerner further said Ariane 6, whose current design would generate work in only five European Space Agency nations and would depend on only these five governments for the full development cost, probably cannot be funded this year if ESA governments also take on an Ariane 5 upgrade and other launcher-related expenditures.

Woerner, who is chairman of the German Aerospace Center, DLR, said Germany wants the new Ariane 6 to use a cryogenic first stage, a cryogenic upper stage and flexible solid-fueled auxiliary boosters attached to the first stage, to give the vehicle more power as needed by the payload. Woerner said substituting the current solid-fueled first stage with a cryogenic stage also would give German industry sufficient work on the rocket to finance about 25 percent of the vehicle’s development. France would assume a 50 percent share, Italy around 15 percent and Switzerland and Belgium would take 5 percent each under the current Ariane 6 development model.

Woerner speculated that a cryogenic first stage, using the experience gained from the current Ariane 5 ECA rocket and its cryogenic main stage, would be less expensive to develop than a solid-fueled version.

A new industrial study concluded that the vehicle could be built for 3 billion euros, plus 750 million euros for the launch pad and related ground hardware. An inaugural flight could occur in 2021. To this cost would be added the usual ESA program management charges, which in this case would be around 250 million euros.

Woerner said this total of 4 billion euros is short of the total likely investment that would be required, and presumes that Ariane 6 and the upgraded Ariane 5 ME rocket share the development cost of a new upper stage with a restartable cryogenic engine.

ESA officials estimate that by sharing development of a common upper stage, the Ariane 5 ME and Ariane 6 development programs will save up to 600 million euros. Under this scenario, Ariane 5 ME would cost about 1.2 billion euros with a first flight in 2017 or 2018.

Other costs need to be added, including a program to upgrade ESA’s Vega small-satellite launcher, and likely new support costs demanded by the Arianespace launch consortium to compensate for the high value of the euro relative to the U.S. dollar.

In total, it would be around 6 billion euros in launcher-related investment that ESA governments would be asked to accept when they meet in December in Luxembourg.

“I cannot imagine ministers are ready to spend that amount right now,” Woerner said. “We in Germany do not have a firm figure on what we can spend, but we can’t afford the current proposals. If the decision is made to have a cryogenic first stage on Ariane 6, we estimate it could cost 20-30 percent less because it borrows from the Ariane 5 ECA cryogenic stage.”

Woerner conceded that Germany’s support for a cryogenic first stage is not only for cost and performance reasons, but also to bolster Germany’s industrial base. He said this long ESA practice — government support in return for guaranteed national work shares, also known as geographic return — is likely the only way to move forward on Ariane 6.

“If you want to privatize launchers, you let industry decide the most efficient way to build Ariane 6 and they do what they want,” Woerner said. “But in this case industry would pay the development costs. We are asking industry to come up with a vehicle that is designed to cost, and that led to a scenario with only five nations. Sweden is left out, for example. And these five nations will be asked to finance the development, putting governments in an overly passive role relative to industry.

“Governments should be a more active participant in the process. We are financing the development to launch our satellites ­— that is our position in Germany. In France, they finance development because rockets are viewed as a strategic asset. We know that France will be leading the development, just as we are leading development of Europe’s contribution to ISS,” he said of the international space station.

“Only a French-German compromise will work. We are not lobbying for a German solution, but a French-German solution.”

The new German ministerial coordinator for space policy, former Justice Minister Brigitte Zypries, is scheduled to meet with her French counterpart, Genevieve Fioraso, the week of March 24 to begin work on a compromise.

Once they determine the way forward on rockets, the two ministers will need to determine Europe’s position on the space station. ESA governments will be asked in December whether to approve a continuing station role until 2020. NASA has proposed that the orbital complex be operated until 2024.

Woerner said the space station agreement, which will depend on Italy’s financial strength as well, cannot be separated from the Ariane discussions. “It’s like a kind of Tibetan prayer,” he said. “Nothing is resolved until everything is resolved.”

Follow Peter on Twitter: @pbdes


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