MEP has been pursuing this long-term goal by using orbital spacecraft, landers, and Mars rovers built by different US contractors to visit Mars. As expected, the program has been very costly to run, gulping billions of dollars over the years. For instance, NASA’s Curiosity Rover, which landed on Mars in August 2012, has a budget exceeding $2.5 billion.

Despite the high cost, research, and time required to run MEP, the space agency continues to run the program because the possible gains have been a motivating force.

Managed by NASA’s Science Mission Directorate, MEP’s four broad goals are to – determine if life ever arose on Mars, characterize Mars’s climate, characterize Mars’s geology, and prepare for the human exploration of Mars.

To better achieve these goals, NASA created a new program under MEP called the Mars Scout Program in the early 2000s to achieve these goals better.