Mars Astrobiology Explorer-Cacher

The Mars Astrobiology Explorer-Cacher (MAX-C), also known as Mars 2018 mission, was a NASA concept for a Mars rover mission, proposed to be launched in 2018 together with the European ExoMars rover. The MAX-C rover concept was cancelled in April 2011 due to budget cuts.

Source: Wikipedia — Mars Astrobiology Explorer-Cacher (CC BY-SA 4.0)