Why is NEOWISE used for galactic observation? I've been studying images from the WISE and NEOWISE missions. WISE used infrared cameras to survey the entire sky. When its primary mission ended in 2010, it was repurposed to look for Near-Earth Objects (described here). What changes to the spacecraft and software were needed in order to change its mission profile? Does it use the same cameras and instruments now as it did when performing a whole-sky survey? My thinking is that a whole-sky survey requires different equipment than a survey to look for small, fast-moving (compared to the stars) asteroids.
After WISE ran out of cryogens to cool its detectors it was re-purposed to look for asteroids.  This was possible because the detectors for 3.4 microns and  4.6 microns could work at higher temperatures than the other detectors and passive cooling gets the spacecraft to 74 K.  It had already finished an all sky survey so there were no new deep space targets for it to study and, with only two detectors, the science would not be as significant, but it has been great as a detector of moving objects like asteroids since, for this, just one band-pass is enough.