Can NASA and ESA work together to explore Mars?

Science : Tight budgets are pushing the U.S. and European space agencies to consider a truly collaborative series of missions to Mars. What would it mean for science?
Did Mars ever harbor life? The multibillion-dollar quest to find out faces an uncertain future on both sides of the Atlantic. The European Space Agency (ESA) lacks the money to carry out its ambitious blueprint for putting a sophisticated lander and rover on Mars’s surface in 2016. And NASA is grappling with major cost increases and delays in its Mars Science Laboratory (MSL) that are eating up funding for future missions.

To avoid hanging separately, say scientists and managers in the United States and Europe, the two agencies must agree to hang together in an unprecedented partnership. This summer they intend to unveil a sweeping plan for a decade of collaboration that could kick off with a joint 2016 mission and culminate a decade later in the return of a martian sample to Earth. “This is a big change,” says David Southwood, ESA science chief. “But we have to think about Mars differently.” Adds his counterpart at NASA, Edward Weiler: “We’ve got to do this together.”