Short answers, pulled from the story.
The Dawn spacecraft was a NASA probe launched in September 2007 to study two protoplanets in the asteroid belt, Vesta and Ceres. It was the ninth mission in NASA's Discovery Program and the first purely exploratory NASA mission to use ion propulsion.
Dawn entered orbit around Vesta on the 16th of July 2011 and completed a 14-month survey before departing in September 2012. It entered orbit around Ceres on the 6th of March 2015.
NASA cancelled the Dawn mission in December 2003 and again on the 2nd of March 2006 amid cost and schedule concerns. Orbital Sciences Corporation, the spacecraft's manufacturer, appealed by offering to build it at cost, and NASA reversed the cancellation on the 27th of March 2006.
Dawn carried two redundant framing cameras, a visible and infrared mapping spectrometer, and a gamma ray and neutron detector called GRaND. The framing cameras were built by the Max Planck Institute for Solar System Research and the German Aerospace Center, the spectrometer by the Italian Space Agency, and GRaND by the Los Alamos National Laboratory.
Dawn used three xenon ion thrusters, derived from NSTAR technology first tested on Deep Space 1, firing one at a time with a thrust of 90 millinewtons. Over the mission this propulsion produced a velocity change of about 11 kilometers per second, powered by a 10-kilowatt solar array.
Dawn ran out of hydrazine fuel by the 31st of October 2018, and NASA declared the mission over on the 1st of November 2018. The derelict spacecraft remains in a stable, uncontrolled orbit around Ceres, where NASA expects it to stay for at least twenty years.