So I just learned my suggestion of using LN2/CO2 in an emergency refrigeration system isn't something I came up with -- LN2/CO2-powered backup refrigeration is

So I just learned my suggestion of using LN2/CO2 in an emergency refrigeration system isn't something I came up with -- LN2/CO2-powered backup refrigeration is in fact a standard option on ultra-low temperature freezers (the kind that get used to store biological samples and stuff): https://www.thermofisher.com/order/catalog/product/6214 https://www.thermofisher.com/order/catalog/product/6214 http://www.helmerinc.com/Assets/helmer/knowledge-center/manuals/ultra-low-freezers/ULT_Service_Manual_360173-A.pdf http://www.helmerinc.com/Assets/helmer/knowledge-center/manu... Given that it's commercially-available on freezers that get used to store critical biological material, there is no reason that a sample vault that stores irreplaceable ice cores can't have a similar, scaled-up version of this as well.