Creating that format required not just the ability to do the mathematics but the ability to understand the engineering context well enough to know what format would be most useful.

The missions the handbook addressed were, in the early 1960s, aspirational rather than immediate.

The Mariner program was beginning to produce the first actual data about Venus and Mars — Mariner 2 reached Venus in December 1962, Mariner 4 returned the first close-up photographs of Mars in July 1965.

But actual landing missions, crewed missions, the full program of solar system exploration that the handbook was helping to plan — those were years and decades in the future.

The handbook was preparation.