PARIS — The French space agency, CNES, expects to freeze the final design of the new-generation Ariane 6 launcher by July, a milestone that will trigger work on a new launch pad in French Guiana whose location has already been decided, according to CNES officials.
The rocket and the launch installation are being designed to operate Ariane 6 at least eight times per year, with a mission goal of 12 flights annually to keep production and operations costs within the targeted 70 million euros ($91 million) per launch.
At somewhere between eight and 12 flights per year, including three or four European government missions, Ariane 6 would no longer need the annual price supports that the current heavy-lift Ariane 5 still requires despite a decade-long run without a failure.
The 20-nation European Space Agency (ESA) pays about 100 million euros per year to the Arianespace commercial launch consortium to permit the Evry, France-based company to avoid financial losses.
The 70 million euro target for Ariane 6 is viewed as an all-in cost that would include about 14 million euros per launch in ground operations and also would include the sales and marketing charges incurred by Arianespace.
Taking advantage of work done years ago on what was then a quarry, CNES officials have selected a site to the north of the Ariane 5’s launch site for Ariane 6, an area called Roche Nicole. Quarry construction left a large pit, now filled with water, that will be used for the Ariane 6 flame trench.
CNES officials say that because of the quarry work, done to support launches of the now-retired Ariane 4 rocket, the flame trench is now the equivalent of 70 percent complete even though no work has begun on it.
CNES managers at the Guiana Space Center spaceport, on the northeast coast of South America, recall the difficulties they had in completing the flame pit for Russia’s Soyuz rocket, which is operated from the European spaceport under an agreement with the Russian government that expires at the end of 2016.
ESA governments, after a long debate between France and Germany, in November agreed to fund initial design work on Ariane 6 while at the same time continuing development of an upgraded Ariane 5 rocket, called Ariane 5 ME, that could fly in 2017.
These governments are scheduled to meet again in late 2014 to decide on full-scale development of Ariane 6 and the final phase of Ariane 5 ME. It is unclear whether ESA governments will be able to afford to do both.
Ariane 6 would fly in 2020 assuming a development go-ahead in 2014. CNES’s Ariane 6 team is operating under the “triple-seven” mantra, meaning seven years’ development, 7 metric tons of satellite payload to geostationary transfer orbit and 70 million euros in launch costs.
CNES estimates that Ariane 6 would cost 4 billion euros to develop, including ESA’s customary program management fees and a 20 percent margin that ESA embeds in most of its programs.
In the spring 2013 edition of CNES’s quarterly in-house magazine, CNES Launcher Director Michel Eymard says the remaining design choices for Ariane 6 should be completed by late April. That deadline has now shifted to early July as CNES, ESA and industry discuss the number and size of solid-fueled boosters that would form the first two stages of Ariane 6.
The basic Ariane 6 design — two or more solid-fueled motors on the first stage, a second stage comprised of the same motor and a cryogenic upper stage based on the Safran/Snecma-built Vinci restartable engine — has been decided by ESA governments.
In addition to doing away with many of the electronics units, cables and connectors now used on the Ariane 5 rocket in favor of circuit boards, Ariane 6’s ground installations must be entirely rethought in the design-to-cost approach, according to CNES.
Ariane 5 uses thousands of cubic meters of helium each year. Ariane 6 will use nitrogen or gaseous hydrogen, both less expensive. The Ariane 5 launcher-integration and final assembly buildings will be scrapped as part of the effort to drive out unnecessary costs.
The Ariane 6 upper stage and the satellite payloads would be mated to the lower stages on the launch pad. To maintain the 12-per-year cadence, two launch-preparation zones will be built.
Eymard said the launcher preparation will adopt a “plug and play” approach. “We erect it, test it and launch it,” he said in the CNES magazine presentation, adding that a last-minute rocket or satellite issue should permit Ariane 6 teams to replace the vehicle or the payload and be ready to launch within 15 days.
With their teeth in a major new engineering project, the enthusiasm for Eymard and his team is palpable. Less so is the one major question hanging over the Ariane 6 project: How will a major role for German industry be found to secure German government support for Ariane 6?