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Big budget, time-travel, mystery adventure series “Terra Nova” is coming to U.S. television in May, from the writers behind hit shows “Star Trek” and “24.”

Executive produced by filmmaker Steven Spielberg, “Terra Nova” is set in 2149 on an overdeveloped, polluted planet. The show follows the adventures of a group of pilgrims who are transported back 85 million years to prehistoric Earth -- complete with dinosaurs -- through a time portal.

“At the core, it is a very emotional show. It is really about a family surviving in this incredible place, trying to give humanity a second chance.

“The philosophical crux is, can Utopia be built? Is it possible?” writer Brannon Braga told television journalists on Tuesday.

Fox said it would broadcast a two-hour preview of “Terra Nova” on May 23 and May 24 before the show returns for 13 episodes in the fall of 2011.

Fox executives said it was the most expensive first-year show ever for the network, but declined to give figures. The program is being shot entirely on location in Australia.

“It’s a very expensive television show. It’s a very ambitious television show,” said Fox entertainment chairman Peter Rice.

The network’s entertainment president Kevin Reilly added; “We’re not in completely unchartered territory here. The start-up cost for the series is definitely on the high end, but it’s not some bank-breaking series.”

“Terra Nova” producers said that environmental themes would play an important role in the show, largely thanks to the close involvement of Spielberg.

Executive producer Rene Echevarria, who started his career writing for iconic TV series “Star Trek”, said one of the themes is the human race not repeating its mistakes, if given a second chance on Earth.

“It is also very important to Mr. Spielberg that we show the continuity of the future we have escaped,” Echevarria said, adding that the Oscar-winning director of movies like “E.T” and “Jurassic Park” was closely involved in all aspects of the show.

“Terra Nova” is expected to build on the appeal of TV shows like “Lost”, the time travel mystery which ended last year, and “Avatar”, the biggest-grossing movie of all time that featured a strong environmental element in its story.