"Lynndel K. Humphreys" writes:
Turn the external tank into a very large Thermos.

It sounds good, but realize that until you get nice clean shiny surfaces and
a very good vacuum level, you don't get very good insulation.

There's a reason people use foam for these things.

Rich (who does a lot of work with cryogen and vacuum insulated systems)

--
Richard W Kaszeta

http://www.kaszeta.org/rich