Curiosity (rover) arm operations were cleared to continue, but drilling remained suspended indefinitely. The "Curiosity" team continued to perform diagnostics and testing on the drill mechanism throughout 2017. "Curiosity" has an advanced payload of scientific equipment on Mars. It is the fourth NASA unmanned surface rover sent to Mars since 1996. Previous successful Mars rovers are "Sojourner" from the Mars Pathfinder mission (1997), and "Spirit" (2004–2010) and "Opportunity" (2004–present) rovers from the Mars Exploration Rover mission. "Curiosity" is long by wide by in height, larger than Mars Exploration Rovers, which are long and have a mass of including of scientific instruments. In
Mars Exploration Rover ancient life, including a biosphere based on autotrophic, chemotrophic and/or chemolithoautotrophic microorganisms, as well as ancient water, including fluvio-lacustrine environments (plains related to ancient rivers or lakes) that may have been habitable. The search for evidence of habitability, taphonomy (related to fossils), and organic carbon on the planet Mars is now a primary NASA objective. The scientific objectives of the Mars Exploration Rover mission are to: The MER-A and MER-B probes were launched on June 10, 2003 and July 7, 2003, respectively. Though both probes launched on Boeing Delta II 7925-9.5 rockets from Cape Canaveral Air Force Station Space Launch