An improved Ariane 5 with greater lifting capacity, or a brand new vehicle built from the ground up?
That’s the question facing ESA this year. The space agency’s two largest contributing nations, Germany and France, are on opposites sides of the issue. So, they have agreed to form two working groups to resolve their differences ahead of ESA’s ministerial meeting in November, Space News reports.
Officials are grappling with three problems: Ariane 5’s payload limitations, high costs, and reliance upon commercial satellites. The rocket must launch communication satellites two at a time, which creates challenges in pairing spacecraft. Communications satellites are also getting heavier, straining payload capacity.
Ariane 5 is also costing European governments money, despite its excellent safety record and commercial success.
ESA governments now pay about 120 million euros ($158 million) per year to the Arianespace launch consortium of Evry, France, to offset fixed costs in Ariane 5 production and permit Arianespace to avoid financial losses.
ESA conducted an audit of the program last year to determine whether cost savings were possible. The answer came back negative, largely due to the “juste retour” policy under which each participating nation must get back roughly what it puts into a program.
France wants to replace Ariane 5 with an entirely new modular rocket that it believes would solve all of these problems.
Early French designs of an Ariane 5 successor rocket show a vehicle of modular design that could place telecommunications satellites weighing between 3,000 and 8,000 kilograms into geostationary transfer orbit, the destination of most commercial spacecraft.
The vehicle would replace both the heavy-lift Ariane 5 and the medium-lift Russian Soyuz rocket, which now operates alongside Ariane 5 at Europe’s Guiana Space Center spaceport in South America.
The Ariane 5 successor, now called the Next-Generation Launcher (NGL), would lift satellites one at a time and be designed from the start to be much less dependent on the commercial satellite market to meet its costs, and much less costly to operate.
Germany is backing the less expensive Ariane 5 Mid-life Extension (Ariane 5 ME) project, which would boost the performance of the rocket in a way that would bring down fixed costs.
In an attempt to position Ariane 5 ME as a cost-saving project, Ariane 5 prime contractor Astrium has said the upgrade — which features a restartable upper stage engine and a 20 percent boost in Ariane 5 performance — could allow ESA to eliminate the Ariane 5 price supports.
The other benefit of this approach is that allow the extremely reliable Soyuz rocket to continue to fly from Kourou for lifting mid-sized payloads. A large investment of funds was made to bring the Russian booster to the South American spaceport, including launch infrastructure and the development of a new upper stage rocket.