LE BOURGET, France — Europe’s plan to join the United States in a two-launch Mars exploration effort in 2016 and 2018 is being thrown into question by concerns raised by France and Britain that the mission has assumed too many risks, European government and industry officials said.

A meeting European Space Agency (ESA) governments set for June 29-30, as well as a possible side conference before that among the four nations paying the biggest share of what Europe calls its ExoMars mission — Italy, Britain, France and Germany — will be the next indication of whether ExoMars is going through a temporary crisis or something more serious.

With what appear to be different motivations, France and Britain have informed ESA that the 2018 mission carrying a jointly developed NASA-ESA Mars rover faces too many doubts to enable them to approve the overall ExoMars project. At ESA, ExoMars’ planned 2016 launch of a Mars orbiter and demonstration lander and the 2018 mission are a single package.

ESA has set a cost ceiling of 1 billion euros ($1.4 billion) for the whole ExoMars mission and has been able to raise only 850 million euros, but this shortfall is not ExoMars’ immediate difficulty.

More serious is the fact that Britain and France, which have agreed to finance 20 percent and 15 percent of ExoMars, respectively, are unsure they can support the project as it stands now because of the doubts they have about the 2018 mission.

At a May 26-27 meeting of the program board for exploration that oversees ExoMars, Britain abstained from voting on a measure to move the mission to ESA’s Industrial Policy Committee for final financial go-ahead. France opposed the measure, which was nonetheless approved.

The Industrial Policy Committee is scheduled to meet June 29-30 to decide whether to accept ESA managers’ argument that the 2016 Mars orbiter, which is indispensable for the 2018 mission because it will relay telecommunications from the rover to Earth, must be placed under contract by July 1.

ESA Director-General Jean-Jacques Dordain, in a June 22 interview here during the Paris air show, said ESA has already lost three months on ExoMars, in part because of NASA’s announcement in March that it could not afford its own rover for 2018 and would like to join ESA in a single rover.

Dordain said delaying the 2016 orbiter’s funding beyond July 1 would add risks to the entire ExoMars program. “If we are not ready to launch the orbiter in 2016, there is no 2018 mission,” Dordain said. “If I delay agreeing to ExoMars financing until questions about the rover are settled, industry could later tell me I am responsible for their missing the 2016 launch window. I do not want this.”

Questions about what NASA intends for this rover, and who will lead its development, have been added to existing concerns that any cost overrun in the 2016 mission will be paid from the 2018 mission despite ESA promises to the contrary.

Yannick d’Escatha, president of the French space agency, CNES, said in a June 21 interview that CNES cares only about the telecommunications relay function of the 2016 mission. Other than that, he said, France’s priority is the 2018 rover. “If the 2016 mission has to be de-scoped to better protect 2018 given the current unknowns, then that is what we propose,” he said.

D’Escatha said waiting a couple of months before approving the overall funding package to give NASA and ESA time to agree on who does what for the rover will not threaten the 2016 launch. “I have never seen a program that can’t make up for that amount of lost time,” he said. “All we want to do is talk about the risks to 2018 and how to reduce them.”

D’Escatha said his concerns about the 2018 mission and what it looks like after NASA and ESA finish their negotiations should not be viewed as a critique of NASA and its decision to scrap, for budgetary reasons, its 2018 rover mission.

“There is no single space agency anywhere that has not confronted unforeseen difficulties that force a change in plans,” d’Escatha said. “But this new element adds unknowns. We would like to be sure that … there is sufficient margin in the budget for the 2018 mission that we can deal with them.”

CNES’s position with respect to the 2016 mission came as a surprise to France’s ESA partners, especially since French industry’s role in ExoMars is concentrated almost exclusively on the 2016 launch.

The most logical place to cut the cost of the 2016 mission is its 600-kilogram entry, descent and landing package, which at one point was considered a priority for France. It may still be for Italy, whose 33 percent share in ExoMars has given its industry — led by Thales Alenia Space Italia — the role of ExoMars prime contractor.

U.K. Space Agency Chief Executive David Williams voiced concerns similar to d’Escatha’s in a June 23 interview, but for more customary reasons of industrial work share. British industry, led by Astrium Ltd., has a lead role in the rover’s development.

Williams said Britain is worried that, despite Dordain’s promises, if the 2016 orbiter development runs into trouble in a few years, it will be too tempting to take money from the 2018 mission. “There is nothing now that legally protects the 2018 mission,” Williams said. He said he was still unclear, as of late June 23, how Britain would vote during the upcoming Industrial Policy Committee meeting.

Williams is also concerned that, while the formal ExoMars declaration at ESA refers to a “European rover,” the requirements of the NASA-ESA joint development effort might put too much of the work in the United States.

Dordain said under ESA rules the committee needs only a simple majority of ExoMars participating nations to approve the measure to sign the ExoMars orbiter contract for July 1.

“I fully understand” the concerns of France and Britain over how best to protect the 2018 mission, Dordain said. “But I plan to proceed with the meeting so we can begin the work. To do otherwise would be irresponsible of me. Assuming I get a promised letter from NASA on June 28 confirming its intention to jointly develop the 2018 rover, I will maintain the June 29 IPC date,” he said, referring to the Industrial Policy Committee.

Dordain said that to accommodate France and Britain and other nations worried about the 2018 mission, ESA will proceed immediately only with those contracts needed to keep the orbiter development on track for a 2016 launch.

He said he is ready to discuss a possible de-scoping of the 2016 entry, descent and landing package, with the savings going to further insulate the 2018 mission from future financial problems. Finally, he said ESA will issue only limited-liability “Authorizations to Proceed” agreements for all ExoMars work that is not critical to keeping the orbiter on schedule.



Despite French Objections, ESA Seeks To Press Ahead on ExoMars

French Concerns Throw ExoMars Plan Into Doubt

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