As of 4 August 2015
On 17 July 2015, the NASA Dawn spacecraft started the spiral descent from survey mapping orbit #2 to the much closer high altitude mapping orbit (HAMO) #3. The descent will move Dawn from 2,700 miles (4,400 km) above dwarf planet Ceres to 915 miles (less than 1,470 km) by mid-August 2015. Dawn’s view of Ceres will be equivalent to looking at a soccer ball from a distance of 13 inches (33 cm).
This graphic describes the descent of Dawn to HAMO. In this point of view, Dawn orbits counter-clockwise. Blue shows ion-thrusting to leave survey orbit #2. Red shows ion-thrusting upon arrival at HAMO. It will take over 20 orbits to complete the transition. The red dashed sections show where Dawn is coasting for telecommunications. Once a week, Dawn pauses ion-thrusting and points toward Earth. Updated flight plans and status checks occur during these communications sessions. Click images to embiggen.
The latest images of surface details can be browsed at this link, updated almost daily. Below is an example of the fine detail in an image posted 3 August 2015. The HAMO will increase detail by 3x.
Mission scientists have converted elevation detail into this color animation of the rotating dwarf planet Ceres. The color scale extends 3.7 miles (6 km) below the surface in purple, to 3.7 miles (6 km) above the surface in red. The bright white spots are as yet un-explained highly reflective material. Some scientists think they are freshly exposed ice due to recent impacts.
Unlike the New Horizons mission which gathered data during a short time of high-speed flyby, Dawn will remain at Ceres permanently in close low-altitude orbit. From the Dawn Press Kit:
The resource that will ultimately limit Dawn’s lifetime is its hydrazine fuel. Once the fuel is exhausted, the spacecraft will no longer be able to point its instruments at the surface. It also will be unable to point any of its ion engines for maneuvering purposes, nor point its antenna at Earth or its solar arrays at the sun. The battery will be depleted in a matter of hours. The spacecraft will remain in orbit around Ceres, but it will cease operating.