The Dawn craft is on target to slip into orbit around the dwarf planet Ceres on Friday after a three-year journey. It'll be the second stop for Dawn, which earlier visited the asteroid Vesta.
Dawn has been snapping pictures of Ceres as it nears the object. Sharper images are expected in the coming months as Dawn spirals closer to Ceres' surface.
Launched in 2007 and powered by ion propulsion, Dawn is the first craft to target two space rocks to learn about the solar system's evolution.