NASA's Perseverance Mars Rover

Ugh, imagine getting to Mars and finding out your camera sensor has a couple of dead pixels

Several cameras have either dead pixels or some sort of contamination on the CCDs, some of those defects were noticed just before launch in final testing, but it was too late to change the replace the CCD or clean inside of the affected cameras :(

All in all the affect on the images is minimal, and only really noticed when they image monotone areas