Russia told European Space Agency officials last week it will partner with Europe on the ExoMars orbiter and rover missions after NASA dropped out of the project in February due to budgetary concerns, according to the Russian space agency.

Artist's concept of the ExoMars Trace Gas Orbiter and descent demonstrator. Credit: ESA
 
The leaders of the space agencies - Roscosmos chief Vladimir Popovkin and ESA director general Jean-Jacques Dordain - met in Moscow on Friday to discuss the joint Mars missions, which are due to launch in 2016 and 2018. ESA calls the 2016 and 2018 missions ExoMars.

ESA began courting Russia as a full partner in the ExoMars project last year as NASA's funding commitment wavered before the U.S. space agency pulled out of the mission in February.

According to a statement by Roscosmos, the Russian space agency, officials agreed the exploration of Mars "represents a joint scientific interest" for both agencies.

Roscosmos and ESA will sign a formal accord on the ExoMars project by the end of 2012, according to a communique issued by the Russian space agency.

Russia will provide two Proton launchers to dispatch the ExoMars orbiter and rover on two flights in 2016 and 2018. Thales Alenia Space is the prime contractor for the 2016 orbiter, which will carry detectors to measure methane and other trace gases in the Mars atmosphere.

A European entry, descent and landing demonstrator will fly to Mars with the 2016 orbiter.

A rover developed by Astrium Satellites in the United Kingdom will launch two years later in 2018. A Russian-built entry, descent and landing package will shepherd the rover to the red planet's surface.

Artist's concept of the ExoMars rover. Credit: ESA
 
Before the agency retreated from the program, NASA was on the hook for both ExoMars launches using Atlas 5 rockets. NASA was also providing research instruments and the rover's landing system, an elaborate apparatus based on the Mars Science Laboratory's sky crane architecture.

ESA's ruling council approved continued funding of the ExoMars program in March, ensuring the orbiter mission stays on schedule for launch in January 2016.

Officials at ESA's next ministerial meeting, scheduled for November, will attempt to sort through an ExoMars funding shortfall.

ESA's member states have subscribed to 850 million euros, or $1.1 billion, in funding commitments for ExoMars. The redrawn ExoMars missions with Russia would cost ESA about 1.2 billion euros, or nearly $1.6 billion.

European officials expect to secure the extra funding before signing formal agreements with Russia.