The cause was heart failure, said Skye Conway, a writer and film producer who was asked by Kyle Johnson, Ms. Nichols’ son, to speak about the family. Ms. Nichols had a long career as an entertainer, beginning as a teenage singer and dancer at a supper club in her native Chicago, and later appearing on television. But she will forever be remembered for her work on “Star Trek,” the cult space adventure series that ran from 1966 to 1969 and starred William Shatner as Captain Kirk, the heroic leader of the starship crew. Leonard Nimoy (who died in 2015) as his scientist and advisor, Mr. Spock, a hyperintelligent humanoid from the planet Vulcan. and DeForest Kelley (who died in 1999) as Dr. McCoy, aka Bones, the ship’s doctor. A striking beauty, Ms. Nichols brought a shrill sexuality to the bridge of the Enterprise. She was generally dressed in a comfortable red doublet and black tights. Ebony magazine called her the “most celestial body in ‘Star Trek’” on its cover in 1967. Her role, however, was both essential and historically significant. Uhura was an officer and a highly educated and well-trained technician who maintained a business-like demeanor while performing her highly meaningful duties. Ms. Nichols was one of the first black women to star in a network television series, making her an anomaly on the small screen, which up until that time rarely featured black women in anything but supporting roles. In a November 1968 episode during the show’s third and final season, Captain Kirk and Lieutenant Uhura are forced to embrace by the inhabitants of a strange planet, resulting in what is widely believed to be the first interracial kiss in its history television. Ms. Nichols’ first appearances on “Star Trek” preceded the 1968 sitcom “Julia,” in which Diahann Carroll, playing a widowed mother who works as a nurse, became the first black woman to star in a non-stereotypical role in a network series. . (A series called “Beulah,” also called “The Beulah Show,” starring Ethel Waters—and later Louise Beavers and Hattie McDaniel—as a maid for a white family, aired on ABC in the early 1950s and subsequently cited by civil rights activists for demeaning portraits of black people.) But Uhura’s influence reached far beyond television. In 1977, Ms. Nichols began a partnership with the National Aeronautics and Space Administration, contracting as a representative and speaker to help recruit women and minority candidates for space flight training. Next year’s class of astronaut candidates was the first to include women and members of minority groups. In subsequent years, Ms. Nichols made public appearances and recorded public service announcements on behalf of the agency. In 2012, after she was the keynote speaker at the Goddard Space Center during a celebration of African American History Month, a NASA news release about the event praised her for helping the cause of diversity in space exploration. “Nichols’ role as one of the first black characters on television who was more than a stereotype and one of the first women in a position of power (she was fourth in command of the Enterprise) inspired thousands of applications from women and minorities,” the release said . “Among them: Ronald McNair, Frederick Gregory, Judith Resnick, the first American woman in space Sally Ride and current NASA Administrator Charlie Bolden.” Grace Dell Nichols was born in Robbins, Ill., on December 28, 1932 (some sources give a later year) and grew up in Chicago. Her father was, for a time, mayor of Robbins and a chemist. At 13 or 14, tired of being called Gracie by her friends, she asked her mother for a different name, who liked Michelle but suggested Nichelle for the alliteration. She was a ballet dancer as a child and had a singing voice with a naturally wide range — more than four octaves, she later said. While attending Englewood High School, she received her first professional gig in a revue at the College Inn, a well-known Chicago nightclub. There she was seen by Duke Ellington, who hired her a year or two later with his touring orchestra as a dancer in one of his jazz suites. Ms. Nichols appeared in many musical theater productions around the country during the 1950s. In an interview with the Archives of American Television, she recalled performing at the Playboy Club in New York while serving as an understudy for Ms. Carroll in the musical Broadway “No Strings” (though never continued). In 1959, she was a dancer in Otto Preminger’s film version of “Porgy and Bess.” She made her television debut in 1963 in an episode of “The Lieutenant,” a short-lived drama series about the Marines at Camp Pendleton created by Gene Roddenberry, who went on to create “Star Trek.” Ms. Nichols appeared in other TV shows over the years – including “Peyton Place” (1966), “Head of the Class” (1988) and “Heroes” (2007). She also appeared on stage occasionally in Los Angeles, including a one-woman show in which she did impressions and paid tribute to black female entertainers who came before her, including Lena Horne, Pearl Bailey and Eartha Kitt. But Uhura would be her legacy: A decade after “Star Trek” went off the air, Ms. Nichols reprized the role in “Star Trek: The Motion Picture” and appeared as Uhura, then the commander, in five consecutive film sequels until in 1991. In addition to a son, her survivors include two sisters, Marian Smothers and Diane Robinson; Ms. Nichols was married and divorced twice. In her 1995 autobiography, Beyond Uhura: Star Trek and Other Memories, she revealed that she and Roddenberry, who died in 1991, had been romantically involved for some time. In a 2010 interview with the Archives of American Television, she said she had little to do with her “Star Trek” cast, but that she stood up for her when studio executives wanted to replace her. When she got the role of Uhura, Ms. Nichols said, she thought of it as a simple job at the time, valuable as a resume booster. she fully intended to return to the stage, as she wanted a Broadway career. Indeed, she threatened to quit the show after its first season and submitted her resignation to Roddenberry. He told her to think about it for a few days. In a story she often told, that Saturday night she was invited to an event in Beverly Hills, California — “I think it was an NAACP fundraiser,” she recalled in the Archive interview — where the organizer introduced her to someone she described as “the your biggest fan.” “He’s desperate to meet you,” the organizer recalls her saying. The admirer, the Reverend Dr. Martin Luther King Jr., was introduced. “He said, ‘We really admire you, you know,’” Ms. Nichols said, and thanked him and told him he was going to leave the show. “He said, ‘You can’t. Can not.’” Dr. King told her that her role as a dignified, authoritative figure on a popular show was too important to the cause of civil rights to give it up. As Ms. Nichols recalled it, she said, “For the first time, we’re going to be seen on TV like we should be seen every day.” On Monday morning, he returned to Roddenberry’s office and told him what had happened. “And I said, ‘If you still want me to stay, I will. Should.’” Eduardo Medina contributed reporting.