>> What provisions are there on restoring these Helium HDDs to working order 10+ years from now on? None. The He will leak and eventually positioning errors w

>> What provisions are there on restoring these Helium HDDs to working order 10+ years from now on? None. The He will leak and eventually positioning errors will become frequent if the drive stays in service long enough. It is not economically feasible to prevent the He diffusion. The drives are designed to lose He slowly enough to exceed their useful service life. The process was developed by HGST (now owned by WD) and it's called HelioSeal. The drive chassis is tin plated steel that is laser welded inside an He filled chamber creating a hermetically sealed enclosure. The pressure inside the enclosure is slightly lower than atmospheric, but He is still lost very slowly through diffusion. Given this process it's difficult to imagine a feasible repair technique; one would have to cut open the chassis and later reseal it in an He atmosphere. Something to consider; there is no means of restoring a flash cell to service after it's been worn out, yet that hasn't prevented widespread and highly successful Flash adoption. I doubt the unserviceable nature of Helium filled drives will impede adoption.