In December 2012, Curiosity's two-year mission was extended indefinitely, and on August 5, 2017, NASA celebrated the fifth anniversary of the Curiosity rover landing. The rover is still operational, and as of May 21, 2019, Curiosity has been on Mars for 2413 sols (2479 total days) since landing on August 6, 2012. (See current status.)
Curiosity's design serves as the basis for the planned Mars 2020 rover, that will carry different scientific instruments.
Animation of the Curiosity rover, showing its capabilities
As established by the Mars Exploration Program, the main scientific goals of the MSL mission are to help determine whether Mars could ever have supported life, as well as determining the role of water, and to study the climate and geology of Mars. The mission results will also help prepare for human exploration. To contribute to these goals, MSL has eight main scientific objectives:
About one year into the surface mission, and having assessed that ancient Mars could have been hospitable to microbial life, the MSL mission objectives evolved to developing predictive models for the preservation process of organic compounds and biomolecules; a branch of paleontology called taphonomy.