I had a conversation with someone about cryonics a few years ago, and they brought up an ineresting problem with the viability of cell over long periods of time

I had a conversation with someone about cryonics a few years ago, and they brought up an ineresting problem with the viability of cell over long periods of time. DNA repair is an active process, and if frozen in Liquid Nitrogen, all molecular activity stops, yet radiation damage can still occur. It seems like on a long interstellar voyage, gamma rays and other cosmic rays would turn an organisms DNA into soup.