AlQa'dah 27, 1435, Sep 22, 2014, SPA -- The National Aeronautic and Space Administration's (NASA's) Maven spacecraft entered orbit around Mars for an unprecedented study of the planet's atmosphere following a 771 million-kilometer trip that started almost a year ago. The U.S. space agency's robotic explorer successfully slipped into orbit around Mars late Sunday, NASA officials said. The $671 million mission is the first dedicated to studying the Martian upper atmosphere and the latest step in NASA's long-term plan to send astronauts to Mars in the 2030s. Flight controllers in Colorado will spend the next six weeks adjusting Maven's altitude, checking its science instruments, and observing a comet passing by at relatively close range. In November, Maven will begin sampling the upper atmosphere while orbiting the planet. It is not designed to land. NASA launched Maven last November, the 10th U.S. mission sent to orbit Mars. Three earlier ones failed.