A lot of NASA's active fleet is getting kind of old. These space probes take years to design and launch, and the trips to their destinations can be even longer.
They don't have to have cutting-edge technology to do good science, which is lucky because some of the newest information we have about the universe comes from spacecraft old enough to have a midlife crisis.
New Horizons launched in 2006 and didn't reach Pluto for its flyby until July of 2015, almost a decade later. It gets all of its science images from a 1-megapixel camera.