2-to-1 resonant orbit better than Lagrangian points?

>
> read Heppeheimer's subsequent book "Toward Distant Suns" (1979, Stackpole Books,
> ISBN: 0-449-90035-5), you'll see he says that orbit was latersupplanted by
> a "rather dull" circular orbit, about half-way to lunar orbit. That's the
> orbit I'm usually referring to whenever I say > HEO.

> Past a
> certain point, O'Neill said to please consider "L-5" as shorthand for "whatever
> orbit they finally settle on as the best".
>

I can see the advantages of a circular HEO versus Elliptical 2:1 resonant orbit.

The main benefit is that the launch window constraint can be removed by injecting all the lunar soil payloads into
near circular "drift" orbits slightly higher of lower than the final HEO. They will then slowly move around and catch up with the processing facility, and a final trim burn or two will achieve rendezvous. This is a common technique today with GEO communications satellites to get them on to station.

You cannot do that with elliptical orbits because they will all have different major axis alignments, unless we severely contrain the launch window.

L-4 and l-5 orbits might also be used with drift orbits ,
but it would be more difficult since those drifts orbits would not be stable and the payloads would have a tendency to wander away and get lost. Hence they would need more active control.