Earlier this year, Lupita Nyong'o was added to the cast of the upcoming Star Wars film, marking the second time that a black woman will appear in the franchise's 37-year history. Femi Taylor appeared in Return of the Jedi, but she wore green makeup and prosthetics, and she played Jabba's dancing slave.

It's strange to see the series only pass that milestone now. But Star Wars is far from the only mainstream science fiction work that has an unrealistic and sometimes telling concept of race. Blade Runner saw a slummy, undesirable world run by Asians. And Her, which took place in a future Los Angeles (though parts of the movie were actually shot in Shanghai), didn't really feature any people of color.

This infographic shows a bigger story:

Science fiction is all about possibility. It has the freedom to create worlds where the cultural rules and norms we live with don't apply. But the genre also metaphorically explores stories about our history and our present. In the 1960s, for instance, Star Trek explored gender discrimination and race, while Battlestar Galactica tackled topics like civil rights, police states, and genocide 10 years ago.

And perhaps that's why the genre can be so frustrating. Despite all of this potential and all of this imagination, our mainstream cultural gatekeepers — the people choosing which movies get made and who gets cast in them — are still prone to ignoring non-white and female characters.

What is science fiction?

It seems likely the main reason we've had a lack of diversity in our science fiction stories is because of the way the genre has been defined.

Rob Latham, an English professor who's a part of the University of California — Riverside's Science and Technoculture studies program, says that the genre suffers from its narrow scope. Science fiction, many people believe, developed from pulp magazines in the 1930s. White men, many of whom were practicing scientists, were the authors for those magazines. Star Wars, Latham says, is an homage to those stories, which tend to be monolithic and dominated by white males.

The trouble with using what came out of these pulp magazines as the working definition of science fiction, which we do, is that it ignores rich storytelling that wasn't in those magazines. Stories that didn't fit this mold of science fiction weren't considered, and people of color and women told stories like that.

Latham believes science fiction existed outside of these magazines in books, other types of fiction, and even more mainstream magazines. W.E.B. Du Bois's apocalyptic story The Comet; George S. Schuyler's Black No More, a tale featuring a machine that could change someone's race; and Pauline Hopkins's Of One Blood are examples of science fiction stories appearing outside of pulp magazines.

"Once you've expanded it that way, there were a lot more women and a lot more people of color writing science fiction," Latham said. "And people's interest in what science meant was also a lot more diverse." Latham and his colleagues won a $175,000 Sawyer Seminar grant in July to build on that idea and explore unacknowledged science fiction by people of color.

This hasn't always gone smoothly.

"What I hear all the time [from certain science fiction fans], is that you're bringing stuff that isn't really science fiction," Latham explained. "But I think if you define [science fiction] in a certain way that it privileges you, the kind of person you are in the world, there's a problem with that."

How non-white people and women have been depicted in science fiction

As the infographic above shows, there have been many times when non-white people haven't been depicted at all in science fiction and fantasy films. That's harder to get away with, considering the effects of globalization and the fact that around 36 percent (and rising) of Americans are minorities.

"My friend Ian Hagemann once said … that when he reads or watches science fiction that inexplicably has no people of color in it, he wonders when the race war happened in the story that killed the majority of the human race, and why the writer hasn't seen fit to mention it, " Nalo Hopkinson, a colleague of Latham's and an author, said.

Some people, possibly the same critics who are resistant to Latham's and Hopkinson's program, try to skirt the question by citing a "color-blind future" or a future where race doesn't matter. Latham and Hoopkinson don't buy that.

"The standard excuse in science fiction is that in the future, there won't be any racism or classism, or we won't have any races because we'll all interbreed and be, I dunno, beige," Hopkinson said. "Perhaps so, but so often, those are really excuses for lazy characterization that erases ethnocultural specificities and differences in experience. Plus, we've been interbreeding for millennia. It's a beautiful thing, but it hasn't yet created the perfect world."

"It's a way of ignoring and erasing the question," Latham added.

This isn't to say that non-white people are never in science fiction and in mainstream sci-fi movies. But that's still a learning process too. In series like Buck Rogers and Flash Gordon, Asian people (or white actors in yellow-face) are the villains, like Ming the Merciless:

Gene Roddenberry's Star Trek, which debuted in 1966, is still considered the ground-breaking standard for including characters like Sulu (George Takei) and Uhura (Nichelle Nichols) in its ensemble. But these characters weren't nearly as well developed as the three (white, male) leads, and there's also the problem of Uhura, who largely does secretarial work.

What Roddenberry did was bold and progressive for his time. Star Trek's vision of diversity may have tilted toward tokenism and chauvinism at times, but the real power of Roddenberry's vision of the future was that he fearlessly addressed the taboo of racial integration by making it the fundamental reality of humanity's future.

"Star Trek, despite all of its flaws, was different. Roddenberry's idea was to have a racially diverse crew," Latham said. "That's an attempt to broaden what it means for people of color to be in the future."

Roddenberry's idea created the foundation for subsequent Star Trek series featuring even more diverse casts. Though the current movie franchise has its questionable casting decisions (like Khan being played by Benedict Cumberbatch), characters like Uhura (now Zoe Saldana) and Sulu (John Cho) are featured prominently.

The genre's sometimes clunky depictions of non-white characters aren't usually done out of ill-will, Hopkinson explains. "In the publishing industry, there are more writers of color being published, and we're generally better at writing from our own experience," she said. "[That's] not to say that white writers can't write characters of color. Some very much can."

Some stories are offering diverse representation. The Hunger Games imagines a world where characters have different skin tones and characters are described as mixed race. Gravity features a female astronaut. Orphan Black is pushing the genre in interesting places. And David Mack, who writes Star Trek books, recently made news by defending his portrayal of a lesbian Vulcan love story.

Representation in mainstream science fiction has improved since Roddenberry's time, but it's still a work in progress.

Why non-white sci-fi matters

If science fiction is about depicting the future, and that future features only white people, then it sends a message to non-white audiences that there's no place for them in the future.

"It must seem to kids that 'I have no place in this future,'" Latham told me.

In a sense, this large, non-white audience for sci-fi has shown that the allure of the genre and its possibilities can outweigh its exclusionary history. Further, there are non-white writers who are pursuing filmmaking, producing, and writing careers in the genre, which is the most important solution to getting more non-white representation on screen. Having more non-white people making decisions — a theme that is true for any industry, really — means more opportunities for non-white characters on screen and non-white stories being told.

The team at UCR points to themes of colonialism and racial struggle — something seen in author Octavia Butler's work and in pieces of Afrofuturism. Conquering or exploring a new world is a running theme in science fiction. Someone who is Native American or black, or someone who grew up in any country affected by waves of colonialism might have a different view than someone who has white, European descendants might.

"To the writers of the '30s and '40s, conquering a new world was a doctrine of manifest destiny," Latham said. "Conquering a new world means something different to people who were brought to the country in chains or were displaced or subject to genocide."

That's why Latham's study could prove so important. Examining non-white sci-fi writers and female writers opens up the possibility of new perspectives and adding depth to well-trodden stories. This also could inspire future writers of color and women to write themselves into the future.

Latham and his colleagues are hoping to study more of these voices when the grant goes into effect next fall.