It was the mathematical infrastructure that would allow future engineers to plan future missions without having to re-derive the orbital mechanics from scratch.

It was, in the specific sense that matters to engineers, foundational work.

Mary Ross co-authored it.

That co-authorship is part of the documented record of the American space program.

The Midpoint Question — What Can Actually Be Known

There is a genuine historiographical question at the center of her story, and it is worth addressing directly rather than maneuvering around it.

The question is: given the classification of much of her most advanced work, what can actually be known about what she contributed?