{ra'ghom} doesn't appear in any dictionaries yet. But if you work back from the components of {ra'ghomquv} and look at the original English, I think it's not too hard to figure out the intent.

{ra'ghomquv} looks like {ra'} "command (v)", {ghom} "group", and {quv} "be honored", so it means something like "honored command group". Presumably it's some holdover from an archaic way of forming compound words. {quv} is a usual Klingon way of describing the most important of something (for instance, {vutwI' quv} "head chef").

Without the {quv}, then, {ra'ghom} suggests a command group, though not the most important commanders involved (who, in the case of the Apollo mission, are probably back in Houston). In other words, {ra'ghom} means "command" in the sense of "a group of officers exercising control over a particular group or operation".