A concept of the European Space Agency's ExoMars Rover. Credit: European Space Agency/AOES Medialab artist's concept

TURIN, Italy — The industrial team leading Europe’s two-part ExoMars mission with NASA will submit a contract proposal in January valued at around 550 million euros ($753 million) for approval by the European Space Agency (ESA), the program manager for prime contractor Thales Alenia Space Italy said Nov. 24.

The 18-nation ESA has already spent nearly 200 million euros on the design and early development phases for ExoMars, which is a deep collaboration with NASA on missions set for launch in 2016 and 2018.

Both will be launched by NASA-provided Atlas 5 rockets as part of the division of roles agreed to between the two agencies. NASA and ESA officials have said the missions, whose work shares took months to sort out, could serve as a model for a future global space exploration strategy being developed by the world’s principal spacefaring nations.

The 2016 mission, to be led by ESA, will include a Mars telecommunications orbiter that will also examine the Mars atmosphere, and in particular will take a further look at still-unexplained methane concentrations that have given some hope that it might be a sign of biological life. It could also be geological activity on the planet. This mission also will include an entry, descent and landing system, a 600-kilogram module that will land on the martian surface in the middle of the seasonal dust storm. It is designed to operate on the surface for less than two days.

The NASA-led 2018 mission will include NASA- and ESA-provided rovers to be lowered to the surface attached by tether to NASA’s sky crane, to be first used on the U.S. space agency’s Mars Science Laboratory mission. The Mars Science Laboratory, a small-truck-sized rover, is scheduled for launch in late 2011. ExoMars program officials say the entry, descent and landing maneuver of the two rovers will be one of the mission’s most stressful moments.

Briefing reporters here Nov. 24, Vincenzo Giorgio, director of Thales Alenia Space Italy’s optical observation and science business line, said the ExoMars industrial team in late October submitted a program proposal to ESA in a 6-gigabyte document. Agency reviews are ongoing, and the industrial team expects to submit its full program contract proposal in January.

Giorgio said the team has been made fully aware by ESA that the mission’s cost ceiling must be respected. ESA Science Director David Southwood had to overcome the resistance of some ESA governments to preserve ExoMars, and in doing so committed to the cap of 1 billion euros. Not all of that money has been secured, but the more than 800 million euros that has been made available is enough to sign the full two-mission industrial contract.

The agency earlier this year received a small boost when Britain’s newly created U.K. Space Agency agreed to pitch in an additional 12 million euros for the ExoMars rover, in which Astrium U.K of Portsmouth, England, has a large role.

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