: At a press conference held yesterday in Washington, DC, NASA official and former astronaut John Grunsfeld announced the seven scientific instruments that would be carried on the agency's next Mars rover. Provisionally named Mars 2020 for its scheduled launch date, the rover will be based on the Curiosity rover, which is currently exploring the red planet's Gale Crater. Like its forebear, Mars 2020 will carry cameras, spectrometers, and meteorological sensors. But its payload will also include the Mars Oxygen ISRU Experiment, which will produce oxygen from carbon dioxide in the Martian atmosphere. In future missions, locally produced oxygen could help power a return trip to Earth and sustain human explorers.