Mars Exploration Joint Initiative

Lore & Background

Despite the termination, NASA continued its own Mars projects: Mars Science Laboratory, MAVEN orbiter, Mars 2020 rover, and InSight lander. In April 2018, a letter of intent was signed by NASA and ESA that may provide a basis for a Mars sample-return mission, though it is unclear if this is a new initiative or a restart of MEJI. The original MEJI vision included a 2016 orbiter (though the ExoMars Trace Gas Orbiter was already a separate ESA-Roscosmos project by 2009, not a joint NASA-ESA mission under MEJI), a joint NASA-ESA rover planned for 2018 (later canceled), and a 2020 network of small landers.

Reader's Guide

The Mars Exploration Joint Initiative represented a significant attempt at international collaboration in planetary science, aiming to pool NASA and ESA resources to maintain a regular Mars exploration schedule every two years. Its importance lies in demonstrating how financial pressures can both drive cooperation and ultimately undermine it. The initiative's collapse in 2012 due to U.S. budget cuts—redirected to the James Webb Space Telescope—highlighted the vulnerability of long-term space exploration to shifting national priorities. The resulting restructuring of ExoMars and the loss of up to 2,000 high-tech jobs underscored the real-world consequences of such decisions. The 2018 letter of intent suggests that the goal of a joint Mars sample-return mission remains alive, but the original MEJI framework was never fully realized. Its legacy is a cautionary tale about the challenges of sustaining multinational space projects amid fiscal constraints.

Did You Know?

• The agreement was signed in October 2009 in Washington D.C. by NASA administrator Charles Bolden and ESA director-general Jean-Jacques Dordain.
• Under the FY2013 budget, NASA's Mars exploration funding was cut by almost 40% from the FY2012 estimate, to $360.8 million.
• The U.S. House Appropriations subcommittee rejected NASA's request to shut down the joint Mars effort on February 16, 2012, demanding a more rigorous debate.