BORDEAUX, France — Europe’s ExoMars mission to launch a lander, telecommunications orbiter and rover to Mars is once again facing collapse after having narrowly escaped cancellation early this year when Russia stepped in to replace NASA as a partner, according to government and industry officials.

Even the program’s biggest supporters would not give it more than an even chance of surviving its next do-or-die session, a May 16 meeting of the council of the European Space Agency (ESA).

At this meeting, ExoMars backers, led by Italy, Britain and France, will be asked to evaluate whether, given the project’s tortured history, it can still make its 2016 launch date for the lander and telecommunications orbiter. The rover, and a Russian-European lander, would be launched in 2018. Both launches would be provided by the Russian space agency, Roscosmos, under the current program proposal.

Of particular concern is whether the addition of a Russian nuclear power source to the lander, which will enable it to function for a full martian year rather than the previously planned several days, can be done quickly enough, and without threatening the orbiter, to make the 2016 launch window.

ESA appointed a three-member team of experts not involved with ExoMars to determine whether the 2016 date remained realistic, and this group apparently has agreed with ExoMars prime contractor Thales Alenia Space that the deadline can still be met.

Enzo Giorgio, ExoMars program manager at Thales Alenia Space, said the company’s ExoMars team has spent several months working on accommodating a Russian radioisotope thermoelectric generator (RTG) to power the 2016 mission’s entry, descent and landing module.

“There are no show-stoppers for this,” Giorgio said in a May 9 interview.

Not everyone has been |convinced.

“Adding the Russian RTG is a good idea, but the ExoMars calendar for the 2016 launch was already tight, and this makes it ultra-tight,” said Richard Bonneville, director of science at the French space agency, CNES. “In our view the current calendar is not credible, and of course the financing issue is not resolved.”

Financing has been ExoMars’ problem from the start. Initially designed as a technology demonstration mission costing around 650 million euros ($845 million), ExoMars expanded to include a science package that swelled the budget to 1 billion euros.

ESA governments in 2008 agreed to that ceiling, but when it came time to commit funds these same governments were able to commit only 850 million euros. NASA was brought in as part of a major trans-Atlantic cooperative Mars exploration effort, and ExoMars was divided into two launches.

ESA officials rejoiced that the U.S. agency’s contribution of one-half of the rover plus two launch vehicles meant the mission would perform valuable science for a price that Europe could afford.

NASA’s own budget issues forced the agency to cancel its planned ExoMars participation. Russia, whose own ambitious mission to Mars’ moon, Phobos, was destroyed in a launch vehicle failure in late 2011, agreed to provide Proton heavy-lift rockets.

Russia also agreed to supply the RTG and several experiments for the 2018 mission, and to build, with European support, a lander for the 2018 mission for launch alongside the now all-European rover.

Russia’s arrival saved ExoMars and opened Roscosmos-ESA negotiations on a broader cooperation in exploration that now includes a sample-return mission from the Moon’s south pole.

The problem was that NASA’s exit meant Europe would need to build the rover on its own, and shoulder other costs as well. The result is that ExoMars’ budget has swelled to about 1.2 billion euros.

For ESA governments that for four years had been unable to reach the billion-euro budget ceiling, a further increase of 20 percent — especially given the current government spending environment in Italy, Britain and France — has put maximum stress on the program.

Johann-Dietrich Woerner, head of Germany’s space agency, DLR, said Germany has never been a major ExoMars contributor and would not be willing to increase its contribution to the project.

Germany is backing its own lunar lander project at ESA and has other priorities that make it impossible to raise its contribution to ExoMars, Woerner said in a May 2 interview.

“This project has already doubled in cost beyond the original idea that we subscribed to,” Woerner said. “We would like to have ExoMars move forward, but we will not be increasing our contribution. Our experts say it should be possible to fly to Mars for 850 million euros.”

Britain and France, ostensibly the second- and third-largest ExoMars contributors after Italy, voted against further funding the project at a meeting of ESA’s check-writing body, the Industrial Policy Committee, earlier this year.

Their gesture was of mainly symbolic value; the two governments knew their votes would not kill the project. But it was a warning to ExoMars backers that neither Britain nor France were convinced that the mission was salvageable.

David Parker, director of technology and programs at the U.K. Space Agency, said he was not certain how Britain would vote at the May 16 meeting. But he made clear in a May 8 interview that the financial challenges are formidable, and may be insurmountable.

Arturo de Lillis, head of the space transportation department of the Italian Space Agency, said May 7 that his government remains fully committed to ExoMars and may be willing to increase its contribution to it. The size of the potential increase, he said, is not certain but it is certainly far less than the 350 million euros the program is lacking.

At this point, ExoMars’ most important supporter may be ESA Director-General Jean-Jacques Dordain, who has demonstrated in the past his ability to find monies where others see only empty pockets.

Dordain told reporters in Berlin May 3 that one source of ExoMars support may be ESA’s science budget, whose spending priorities are governed by strict procedures that are outside Dordain’s control.

Government and industry officials said Dordain has been working on having Roscosmos provide a Proton rocket for Europe’s Juice mission to the Jupiter region in 2022. That would leave around 150 million euros for the science program to use on ExoMars.

A lesser amount of financing may be found by adding ExoMars to the science program as a so-called Mission of Opportunity. Bonneville, who in addition to his CNES role is the current president of the Science Program Committee that decides space science priorities, said that even if the committee backed the idea, it would mean no more than “a few 10s of millions of euros” for ExoMars.

Officials have said that, in recent weeks, Dordain has gone so far as to propose that construction on ESA’s new headquarters be delayed by two years, and that the money be spent on ExoMars.



ESA Ruling Council OKs Funding for Mars Mission with Russia

Europe To Press Ahead with ExoMars Plans Without NASA

ESA Formally Invites Roscosmos To Join ExoMars Mission as Full-fledged Partner

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