Lakes on Mars Mons (previously informally named "Mount Sharp" to pay tribute to geologist Robert P. Sharp) rising higher from the crater floor than Mount Rainier rises above Seattle. Strong evidence uggests that Gale Crater once held a large lake. On August 6, 2012, the Mars Science Laboratory landed on Aeolis Palus near Aeolis Mons in Gale Crater. On August 5, 2012, the Mars Science Laboratory rover, ""Curiosity", landed at the foot of a layered mountain inside Gale crater. As the mission progressed, discoveries and conclusions were released from NASA detailing the mounting evidence that Gale once contained a large lake. On September
Mars sample-return mission request of NASA and the NSF, declared a MSR campaign its highest priority Flagship Mission for that period. In particular, it endorsed the proposed Mars Astrobiology Explorer-Cacher (MAX-C) mission in a "descoped" (less ambitious) form, although this mission plan was officially cancelled in April 2011. In September 2012, the United States' Mars Program Planning Group endorsed a sample-return after evaluating long-term Mars' plans. The key mission requirement for the planned Mars 2020 rover is that it must help prepare NASA for its MSR campaign. which is needed before any crewed mission takes place. Such effort would require three additional vehicles: