PARIS — One of Europe’s principal companies involved in the maintenance of satellite and launch-pad facilities says it has already reduced per-launch costs as Europe moves from one launcher to three but has not yet determined how much lower it can go.

That question puts Mulhouse, France-based Clemessy, which manages power, lighting, security and other functions for facilities at Europe’s Guiana Space Center spaceport in French Guiana, on the front lines of the current debate about the direction Europe’s launcher sector should take.

Government ministers from the 19-nation European Space Agency (ESA) are scheduled to decide in November whether the current heavy-lift Ariane 5 ECA vehicle, which has been unable to generate a profit despite its long success, should be upgraded or replaced.

Current Ariane 5 contractors, led by Astrium Space Transportation of France and Germany, argue for the upgrade, which would add 20 percent to the current Ariane 5 ECA’s payload-carrying capacity for commercial telecommunications satellites.

Key to this argument is the promise that the Ariane 5 contracting team in Europe and French Guiana will be able to use the added payload power, combined with reduced costs of operating and maintaining Ariane 5, to permit ESA governments to stop making annual Ariane 5 support payments.

Those payments average 120 million euros ($150 million) per year.

Astrium Space Transportation has submitted a letter to ESA promising that, under certain conditions, the support payments can cease once the upgraded Ariane 5, called Ariane 5 Midlife Evolution, is in operation around 2018.

Clemessy is one of about 20 companies that, under pressure from the Evry, France-based Arianespace launch consortium and the French space agency, CNES, agreed to reduce their costs in return for new five-year contracts. In December, CNES signed 16 of the contracts and Arianespace signed 14.

The French government pays about half the cost of the Guiana Space Center each year, with other ESA governments paying the remaining portion.

The combined value of the work is 700 million euros over five years. Joel Barre, who until a recent reassignment was director of the Guiana Space Center, said at the time that the overall result is around 10-15 percent reduced costs.

Simon Klingler, commercial director of Clemessy’s aeronautic and space division, said his company and others were able to commit to the cost reductions by adding fresh work to their contracts. The new work is principally an extension of Clemessy’s former Ariane 5-dedicated contracts to the Europeanized Russian Soyuz rocket, which is operated alongside Ariane 5 at the Guiana Space Center (CSG).

Klingler said the economies hinge on Arianespace’s ability to time Ariane 5 and Soyuz launches so that they do not occur too close together. That way, launch preparation teams can move from one vehicle to the other, reducing the per-launch charge.

“If we have an engineer at CSG, he would have little to do during those periods when Ariane 5 was not preparing a launch,” Klingler said Sept. 5. “Now they can move to Soyuz, which shares the cost and reduces the charge to the Ariane 5 launch.”

Klingler declined to speculate on whether further savings could be wrung from the network of companies that manage Ariane 5’s ground facilities and operations around the launch pad.

“We made a serious effort to get the costs down,” he said of the Guiana Space Center contract with Arianespace and CNES. “I am not sure the companies involved can go much further. We’ll have to see. There may be room for economies on the launch vehicle side, meaning on the rocket itself, but this is very difficult.”

Clemessy’s aeronautics and space division reports annual revenue of about 70 million euros, equally divided between the two business sectors.

In addition to the French Guiana work, Clemessy maintains satellite and launcher facilities for Ariane 5 contractors in Friedrichshafen and Bremen, Germany; and in Vernon and Les Mureaux, France.

The company performs satellite-preparation facility maintenance at Russia’s Baikonur Cosmodrome in Kazakhstan on behalf of the French-Russian Starsem company that manages Soyuz commercial launches from Baikonur.

Clemessy has broadened its portfolio to include spacecraft test benches. It is one of the companies that has a stake in Europe’s ExoMars exploration program, a two-launch effort including a telecommunications orbiter and a rover vehicle that, like the future of Ariane 5, will be decided by ESA governments in November.

Still, the debate about the Ariane 5 will be the most important topic before European governments in the weeks leading up to the November ESA conference.

For Clemessy, the choice to design a new rocket from the ground up would present a long-term opportunity. But because rockets’ ground systems are among the last pieces to be inserted into a rocket development program, it would do little for the company in the short term.

The Ariane 5 Midlife Evolution, on the other hand, would guarantee work for Clemessy immediately, Klingler said.

Peter B. de Selding was the Paris bureau chief for SpaceNews.