In addition to all of its other work this month, the sophisticated robot has continued some specialized measurements it began at lower altitude. Being higher up does not cause as much of a reduction in the sharpness of some pictures as you might think. Held in a looser gravitational grip, Dawn’s orbital velocity is lower at higher altitude. As a result, observations that require a long exposure are not affected as much by the spacecraft’s movement. That’s helpful for some of the spectra and photographs. For example, Dawn has used its camera to peer into craters near the north and south poles that are in shadow continuously, every Cerean day of the Cerean year. These special locations might trap water molecules that escape from elsewhere on Ceres where it is too warm for them. With the benefits of a wider view from a higher altitude and a more predictable orbital path, Dawn’s coverage this month of these intriguing areas, faintly illuminated by sunlight reflected from crater walls, has been more complete than at lower altitude.

This fifth Ceres campaign was intricate and intensive, but it stayed right on the tight schedule. Dawn began collecting data as planned on Oct. 16 and finished transmitting its findings to Earth on Oct. 29. And it was exceedingly productive, yielding almost 3,000 photographs plus a great many infrared spectra and visible spectra containing a wealth of new information about Ceres.

This week controllers are going to check out the backup camera, as they do twice a year to confirm that it is still healthy and ready to take over should the primary camera develop a problem. Nevertheless, the primary camera remains fully functional. The team also is planning to switch to the backup set of reaction control system thrusters. Dawn has flown for so many years without a full complement of reaction wheels that these hydrazine thrusters have been used far more than anticipated when the ship was designed. They are healthy, but ever-cautious engineers do not want to overuse them.