PARIS — The multibillion-dollar U.S.-European Mars exploration program has suffered a serious —  but not fatal — blow with NASA’s confirmation that it can no longer afford to launch its own rover alongside a European rover in 2018, European government and industry officials said.

Both sides have agreed to design a larger, common rover that will meet U.S. and European mission goals, with a Joint Engineering Working Group scheduled to present a detailed design by late this summer.

That alone would not put the joint Mars exploration program in crisis. But for the 18-nation European Space Agency (ESA), the 2018 mission was designed and financed as a single program that includes a 2016 launch with NASA of a Mars orbiter and an experiment package to test entry, descent and landing technologies.

With the 2018 mission facing a major modification, ESA in mid-April issued stop-work orders for all contracts related to its ExoMars program, including the 2016 mission. That decision has put additional stresses on a European ExoMars effort that, for the 2016 launch, was already facing deadline and financing issues that have nothing to do with NASA.

The NASA decision may end up relieving some of the financial pressure. A single rover — even one larger and more complex than either of the two it replaces — should cost less than two separate rovers, according to preliminary estimates by industry. But the precise cost remains to be seen.

For now, the stop-work order of most concern relates to the 2016 mission.

ESA Science Director David Southwood said the agency has set itself what he agreed are exceptionally tight deadlines to secure tentative approval from its member states on the reorganized rover mission in 2018 and, in parallel, a sharp cost reduction demanded of industry for the 2016 mission.

“I would say that’s true, and Easter vacations will have a problem,” Southwood, who is known for his understatements, said in an April 20 interview when asked whether ESA and the ExoMars industry team are being asked to move with unaccustomed speed.

ESA managers have now set about the task of persuading the principal ExoMars contributing nations — Italy, France, Britain and Germany — that their industries’ work share will not be sacrificed in the new scenario. Almost as important are the smaller ExoMars contributing nations, whose national industries often have limited areas of expertise and thus cannot be moved from one part of a mission to another as easily as companies in the larger nations.

ESA plans to ask its Industrial Policy Committee, which writes the agency’s checks, to approve interim funding for the 2016 mission on May 11. On May 26-27, ESA’s Program Board for Human Spaceflight, Microgravity and Exploration, which oversees ExoMars, will be asked to give its endorsement to the program’s new structure.

While word that NASA’s Mars rover was on the budget chopping block had circulated for weeks, it was not until a NASA-ESA meeting March 29 at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., that the U.S. agency formally advised ESA that the rover could not be built. NASA said at the meeting that its budget for the 2018 mission — not including launch aboard a United Launch Alliance-built Atlas 5 rocket — would drop from an originally estimated $3.5 billion, past the $2.5 billion recommended by the U.S. National Research Council and end up at around $1.2 billion.

Calculating the effects of the decision on Europe’s ExoMars plans, Southwood said he feared that the entire NASA-ESA Mars exploration program, which had taken months to establish and may be Southwood’s most enduring legacy as science director, was about to collapse.

“You could say it’s like kicking over a castle,” said Southwood, who is retiring on May 1. “I admit that in the early part of the meeting, I thought, ‘How do we handle the breakup of a marriage?’ especially as it came just after the L-class decision.”

Southwood was referring to NASA’s March announcement that it could not participate in any substantial way in any of the three Large (L)-class science missions that ESA was considering for the next decade. Of the three missions that reached ESA’s final competition, two depend heavily on NASA participation.

ESA has now given all three L-class mission teams until early 2012 to regroup and reconsider their projects in light of NASA’s decision. But for two of the three missions, NASA’s absence may be equivalent to running a race with only one leg.

After the initial shock, and learning what NASA proposed, Southwood concluded that ExoMars could be reoriented without overly upsetting the delicate industrial landscape that ESA must construct for each mission in exchange for financing.

“Ed Weiler and NASA have been extremely open and upfront with us,” Southwood said, referring to his NASA counterpart. “I believe we can sell it [the combined rover] to our delegations and still preserve everyone’s industrial stake. In fact this could be a nice solution to the budget problem — as long as it does not get lost in ITAR.”

ITAR, or the International Traffic in Arms Regulations, is a U.S. regulatory regime that for a decade has treated satellites and most other space technology as weaponry. The ITAR regime has made discussions between U.S. and non-U.S. scientists — even on subjects such as planetary parachutes — difficult and occasionally impossible.

The combined rover would include the nine-instrument Pasteur payload that had been intended for the European ExoMars rover, Southwood said. It would notably include a drill to take samples beneath the surface, and feature a large area to enable soil samples to be cached — a U.S. priority — for several years while waiting for a future sample-return mission to collect them for return to Earth.

“Our merged rover’s design leverages both partners’ goals and capabilities and assets,” said Jim Green, director of NASA’s Planetary Science Division. Speaking April 18 to the NASA Advisory Council’s planetary science subcommittee, Green said a joint ESA-NASA engineering working group established April 6 is drafting a technical solution to the joint mission that accounts for NASA’s funding constraints.

Doug McCuistion, who heads NASA’s Mars exploration program, emphasized that the two sides are still sorting out who brings what to the table. However, he told the subcommittee that NASA would provide the rover’s descent stage, based on the Mars Science Laboratory (MSL) mission slated to launch late this year, while ESA would likely continue work on the drill planned for the original ExoMars rover.

“We’re going to look and see what the best combination of capabilities and assets are and how we go about building a joint rover,” McCuistion said. “It’s not going to look like ExoMars, it’s not going to look like MSL. It’s going to be something new.”

The drama of NASA’s decision is not the only problem ExoMars has had at ESA. The original two-launch program, which had been given a budget not to exceed 1 billion euros ($1.45 billion), was already gasping for financial air.

On Feb. 11, the ExoMars industrial team, led by Thales Alenia Space of France and Italy, submitted an ExoMars manufacturing proposal that was about 40 percent over ESA’s cost target of 575 million euros. These figures do not include full operations once at Mars.

The breakdown ESA had sought was 135 million euros for the Mars orbiter and 145 million euros for the entry, descent and landing demonstrator, both to be launched in 2016; and 240 million for the ExoMars rover, plus 55 million euros for project management, the launch campaign and initial operations.

On March 3, ESA and the ExoMars industrial team met to find ways to reduce these costs. On March 15, the two sides met again and found savings of just 50 million euros — 200 million euros short of what was demanded.

ESA officials now say that follow-up meetings with industry have identified savings totaling 200 million euros. ESA has further offered to waive its usual program management fees, which could result in 50 million euros of savings.

ExoMars prime contractor Thales Alenia Space has not yet signed a contract incorporating these new prices, which would bring the contract value to just over 600 million euros. Every week that goes by without a restarted contract for the ExoMars Trace Gas Orbiter, to be launched in 2016, puts that launch date under greater pressure. Government and industry officials agree that missing the 2016 launch date would be disastrous for the 2018 mission since the 2016 orbiter will also serve as a telecommunications relay for the rover. Favorable launch opportunities for Mars-bound spacecraft occur roughly every two years.

In an April 22 statement in response to Space News inquiries, Patrick Maute, director for optical observation and science at Thales Alenia Space, said: “We have now arrived at a time when it is absolutely necessary to make concrete, definitive decisions on the 2016 mission so that we may begin cutting metal for this in June. There is no time to lose, especially given the fact that the 2016 mission is indispensable for the 2018 mission that will follow it.”


Amy Svitak contributed to this story from Washington



U.S., Europe Plan Single-rover Mars Mission for 2018

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