"This event was a long time in the making and took a great deal of collaboration," Roscosmos head Vladimir Popovkin said after signing the deal with ESA Director Jean-Jacques Dordain in Paris.

Russia's involvement in the ambitious mission could boost the status of its once-pioneering space agency after a litany of costly and embarrassing failures.

The delays in agreeing the mission hinged on the extent of Russia's participation, according to Russian space experts who said Moscow had seemed to reach its goal of full partnership.

"The agreement implies that Russian scientists and engineers will become full-fledged participants in all the international scientific and technical groups," Roscosmos said in a statement.

What was to be Russia's first deep space mission in more than two decades - the Phobos-Grunt mission to scoop up soil samples from Mars - was among five botched launches that damaged Moscow's reputation as a reliable launch partner.

European governments have so far committed 850 million euros ($1.1 billion) to the mission. The funding cap has been set at 1 billion euros but delays and changes to the scientific aspects of the project are expected to drive up the price tag.

Even though NASA pulled out, it will still provide radio communications equipment, an important organics experiment and engineering and mission support.

The United States also plans to follow up its Curiosity rover with an identical probe, to launch in 2020. It has not yet decided if it will cache samples for a future return to Earth.

The US National Academy of Sciences in 2011 ranked a Mars sample return mission as its top priority in planetary science for the next decade. The long-term goal of the US human space program is to land astronauts on Mars in the 2030s.

Reuters