But like the Starship Enterprise, Atomic Arts' five year "Star Trek" mission is coming to an end.

PORTLAND, Ore. -- For five years now, Portland "Star Trek" fans have been treated to an outdoor, in-the-park performance of an episode of the original "Star Trek" television series put on by an organization called Atomic Arts . They call it "Trek in the Park."

These performances -- about one hour, like the TV show -- have only been growing in popularity through the years (at least 600 people turned out for Saturday's show) but the founders have decided to move on to new creative endeavors. I caught Saturday's performance of "The Trouble with Tribbles" -- this year's show -- in Portland's Cathedral Park amphitheater. The last shows will be at 5 p.m. Saturday and Sunday, if you happen to be making a trip to Portland this coming weekend.

There's almost no set -- save for a captain's chair -- but the actors are clad in the familiar Starfleet uniforms. The show has a lot of fun touches, including theme song vocalists who come on stage and wail out the show's theme music.

Fans spotted Saturday included several in "Star Trek" T-shirts. A woman dressed as a Klingon took a smoke break in the shade of the St. John's Birdge above the park amphitheater.

Each year for the past five years during all the full weekends in August, the troupe performed a different episode each year. ("Journey to Babel" was the 2012 show; "Amok Time" was done the first year.)

It's a fun gathering of die-hard fans. The performances are decent if not imitations on the original actors. But mostly it's about having a fun evening out with fellow Trekkers, Trekkies and others who appreciate campy pop culure.

For this year's show, fans from all over the Portland metro area crafted the little furball characters just for "Trek in the Park." Hundreds of them get tossed on stage during the performance and also fall out of a cabinet and bury Kirk (Adam Rosko, Atomic Arts co-fouder and director of the show), just as they did in the TV show.

David Gerrold, who wrote the tribbles episode, was a surprise guest in the audience at Saturday's show and made a few remarks afterwards, thanking fans for their dedication to "Star Trek" and recalling his experience writing the episode as a college student (!?!) 46 years ago. Garret Wang, who played Harry Kim on "Star Trek: Voyager," was scheduled to make a cameo appearance this past Sunday.