Memory corruption from cosmic rays may be more common than your intuition suggests. This article cites a 2009 study of a large cluster that found single-bit ECC corrections occurring about 1 per minute per TB, and uncorrectable double-bit errors at a rate of about 1 per year per TB:

http://spectrum.ieee.org/computing/hardware/how-to-kill-a-su....

Whether this is frequent enough to warrant consideration depends on your application, but there are definitely people here who care enough about how their systems recover after errors of this sort that it's not an absurd suggestion.