NASA successfully launched the Mars Atmosphere & Volatile Evolution (MAVEN) mission last week. The mission is primarily designed to orbit the Red Planet and study its atmospheric chemistry. Weighing 5,400 lb, the MAVEN craft’s suite of instruments includes spectrometers and particle analyzers that will collect data from Mars’s upper atmosphere for one year. Information sent back by the craft—which will only orbit, not land on, Mars—will help scientists understand why a planet that some 3 billion years ago was characterized by liquid water and a thick atmosphere is now mostly dry. The $671 million MAVEN mission was nearly sidelined until 2016 because of the 16-day federal government shutdown in October. But because the mission has a crucial secondary role as a communications relay for NASA’s Mars rovers, lawmakers were convinced that work on the mission needed to continue during the shutdown.