In Star Trek: The Original Series, Uhura didn’t get too many chances to be a hero, unsung or otherwise. She handled communications, which meant the beginning and end of her heroism mostly began with receiving galactic phone calls. Fortunately, the later films gave Uhura more to do, and she quickly established her value among Kirk’s crew.
For example, in Star Trek III: The Search for Spock, Uhura becomes Kirk’s personal hero when she helps him hijack the Enterprise so he can head to the Genesis Planet on a crazy quest to save Spock’s body and Dr. McCoy’s mind. By the transitive property, Uhura played a vital role in saving Spock, someone who goes on to save countless lives.
She also plays a big role in the subsequent film by fine-tuning the transmissions from the mysterious Probe, allowing Spock to determine that the alien vessel is inexplicably generating whale song noises.
