Mary Ross did those calculations.

What she did them for, exactly, and what the results were used to design or to enable — that is where the documentary record becomes partial and the obligation to honesty about uncertainty becomes paramount.

Why Secrecy Is A Documentary Problem, Not An Excuse

It is worth pausing here to say something directly about the way Mary Ross’s story is sometimes told.

There is a version of the story that fills in the classified gaps with confident specifics — that describes her working on specific named systems, that attributes specific design decisions to her influence, that presents the classified work as simply confirmed and moves on.