From April 23 to May 9, 2015, "Dawn" entered an RC3 orbit (Rotation Characterization 3) at an altitude of . The RC3 orbit lasted 15 days, during which "Dawn" alternated taking pictures and sensor measurements and then relayed the resulting data back to Earth. On May 9, 2015, "Dawn" powered its ion engines and began a month-long spiral descent down to its second mapping point, a Survey orbit, three times closer to Ceres than the previous orbit. The spacecraft stopped twice to take images of Ceres during its spiral descent into the new orbit.