They've been able to build hard-drive-sized cartridges that hold over 100Tb and are pretty never indestructible for years ... the reader devices are too big, slow and expensive to be commercially viable though — haven't heard much new on that front in a while ... of course the 1 × ½ × 3/16 inch 1TB flash drive I just measured would pack 120TB in the same space ... roughly the same as 128Gb transflash/MicroSD chip (those are available too) ...