NASA's next mission to the surface of Mars will be a new rover to be launched in July/August of 2020 (and, hence, currently just referred to as "the Mars 2020 rover"). To save money and reduce risk by relying on many proven technologies, the rover is built from approximately 90% spare parts from the Curiosity rover that landed on Mars in 2012. However, the Mars 2020 rover has a dramatically different mission and payload, as it is being designed to be the first step in a longer-term, multi-mission program of robotic sample return from Mars. The Mars 2020 rover will use multispectral stereo imaging, spectroscopy (visible, IR, and Raman), microscopy, elemental analyses, ground-penetrating radar, and a complex arm-mounted coring system to collect and store onboard 20 or more small samples of Martian rock, regolith, and atmosphere over the course of an approximately 1.5 Mars year mission beginning in February 2021. The samples will be cached in one or more depots along the rover's traverse for a future robotic mission(s) to collect and return to Earth later in the 2020s. The landing site, selected after a 3-year community-wide process, is an ancient sedimentary delta deposit on the floor of ~50 km diameter Jezero crater. On Earth, deltas are low-energy environments in shallow lakes or seas that are excellent places for the preservation of organic materials and other potential signs of past habitability. Jezero's deltaic sediments are sourced from ancient highlands materials that date back to the earliest epoch of Mars history, when the climate was warmer, wetter, and putatively habitable. This presentation will review the rover mission's goals, payload, landing site, and role in the worldwide longer-term program of robotic and eventually human exploration of Mars.