38:37 https://www.youtube.com/watch?v=JZLpbhsE72I&t=2317s in Jay Forrester's "The Design Environment and Innovations of Project Whirlwind" talk ( https://www.computerhistory.org/collections/catalog/10270308... ):

There was a desperate search for better memory. We seriously considered. at one stage. renting a television microwave link from Boston to Buffalo and back so that one could store something like 3,000 bits in the 3 milliseconds of round-trip transit time.

Though I'm not sure why they wouldn't have just used a delay line for that task: that form of memory was already in use in computers, as discussed by Forrester himself from 11:15 https://www.youtube.com/watch?v=JZLpbhsE72I&t=675s .