  The NASA Planetary Data System hosts millions of images acquired from the
planet Mars. To help users quickly find images of interest, we have developed
and deployed content-based classification and search capabilities for Mars
orbital and surface images. The deployed systems are publicly accessible using
the PDS Image Atlas. We describe the process of training, evaluating,
calibrating, and deploying updates to two CNN classifiers for images collected
by Mars missions. We also report on three years of deployment including usage
statistics, lessons learned, and plans for the future.
