Luc Besson is ready to play the summer's biggest wild card.

The French filmmaker behind box-office hits The Fifth Element and Lucy is set to unveil his most ambitious science-fiction spectacle yet, Valerian and the City of a Thousand Planets (in theaters Friday). Based on a French comic-book series, the 3-D adventure stars Dane DeHaan and Cara Delevingne as special operatives tasked with saving an intergalactic metropolis from an unknown force.

But with no big-name actors, a hefty $180 million budget and out-there source material that's little known to U.S. audiences, Valerian risks becoming the latest sci-fi flop in a recent string of many. Despite decent reviews from critics (72% positive on aggregate site Rotten Tomatoes), the movie is expected to open with just $18.5 million, easily bested by World War II drama Dunkirk's predicted $55.5 million, according to

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If projections hold, it will come in below the first-weekend starts of bombs Tomorrowland ($33 million against a $190 million budget), Disney's futuristic theme park-inspired outing with George Clooney, and John Carter ($30 million against a $250 million budget), the critically panned adaptation of Edgar Rice Burroughs' A Princess of Mars. Anything less than $20 million would put it on par with Jupiter Ascending ($18.4 million on a $176 million budget), Lilly and Lana Wachowski's space opera starring Channing Tatum and Mila Kunis.

With other sci-fi disappointments including Alien: Covenant, Life and Passengers this past year, why do studios keep ponying up big bucks for the genre?

"There's a desire to discover a new franchise, the next Star Wars (or)Star Trek," says Erik Davis, managing editor of movie-ticket site "They hope to stumble on a pot of gold. Sometimes we see that with something like The Matrix and sometimes we see the opposite with something like John Carter."

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Besson, whose independent studio EuropaCorp produced Valerian, recently told Nerdist that he has already written a sequel. But Newsweek reports that the first entry will need to make at least $400 million globally to even turn a profit, which could prove difficult as it competes against other established franchise movies such as Spider-Man: Homecoming and War for the Planet of the Apes, both of which are also targeted to younger male moviegoers.

"It's awkwardly sandwiched in between those titles, so it'll have a hard time finding that audience," says Daniel Loria, managing editor at "Luc Besson is one of the (filmmaking) visionaries of this generation, but it will be difficult for him to stand out with this release date."

But sci-fi has a tendency to surprise. Just look at the $2.8 billion worldwide take of James Cameron's alien romance Avatar, whose long-gestating four sequels are slated for release starting in 2020. Then there's the unexpected success of Marvel's Guardians of the Galaxy ($333 million) and its Vol. 2 ($386.7 million), whose unlikely superheroes (a tree and raccoon, among them), were "quirky enough that audiences fell into it," Loria says.

Factor in lower-budget, higher-brow fare such as Arrival ($100.5 million), The Martian($228.4 million) and Gravity ($274 million) — all of which were best-picture Oscar nominees — and it's become increasingly difficult to predict which movies will land with audiences.

"It's hard to say what works and what doesn't," Loria says. "I don't think there's a general trend or formula of sci-fi that is or isn't working."