Scrubbing
Beginner
Reading memory again and again and fixing any mistakes, before they pile up.
Novice
Regularly reading through memory (or an FPGA’s configuration), correcting any flipped bits, and writing the clean data back, so errors don’t accumulate.
Expert
The scrub interval is set against the upset rate, so the chance that two upsets land in one code word between scrubs stays acceptably low.
Explained in Space (Industries).