I've never watched much I Love Lucy. It was before my time. But I had a vague idea who Lucille Ball was. What I didn't know until just a few minutes ago, when PBS informed me, was that she divorced Desi Arnaz and bought his share of Desilu Productions, making her the first female head of a major Hollywood Studio. Under her leadership, the studio produced a lot of forgettable shows, but it was also home to the original Star Trek.
I Love Lucy ran 180 episodes. Star Trek spawned 6 different series of 726 episodes, ten movies, books, video games, an entire subculture, and it's not over yet. Star Trek has been wildly successful. A temporary page on Wikipedia, not yet included into the main article on Star Trek, gives a history of Star Trek in which Lucille Ball was pivotal to the series making it past a pilot:
NBC rejects the pilot as being too cerebral for 1965 television audiences. However, they like the concept enough to allow Roddenberry to film a second pilot. (This needs to be checked, but I believe "Inside Star Trek" indicates that the decision was the result of Lucille Ball playing hardball with the network regarding other Desilu productions and therefore championing Trek.)
If this is all true, it's especially odd that everyone knows Lucille Ball from I Love Lucy, but hardly anyone knows of her role in the much more successful Star Trek series.