It's not analoguos at all. If NASA really wanted what was on those tapes, they could get it. There are companies in existence today that can read all tapes of backup tapes, even dating back 20 or 30 years. If they really wanted to spend the money, they could contract it out to a company to have all the media cataloged and labeled properly. And besides all that, I'm sure they've got most of the information on servers spread throughout the agency. No one I know makes backups and then deletes the original data (except maybe LFL )
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