She was, by the accounts of colleagues who knew her during this period, one of the more mathematically sophisticated members of the team she worked with.

The specific nature of mathematical sophistication in this context means something concrete: it means the ability to handle the differential equations that govern flight dynamics, the orbital mechanics that govern the behavior of objects moving at high speeds along curved paths through and above the atmosphere, the physical models that connect the behavior of air and vacuum and gravity to the performance of aircraft and missiles and satellites.

Those problems were hard.

They required the highest levels of mathematical training that American universities could provide, applied to physical situations that were, in many cases, genuinely new — situations where the known physics provided the framework but where nobody had ever actually done the specific calculation before.