Long relegated to the Air and Space Museum’s basement gift shop, “Star Trek’s” USS Enterprise has moved to the central atrium. The newly restored, 11-foot-long studio model of the fictional starship, used for special-effects shots in the original TV series, will be unveiled Tuesday. (Just in time for the museum’s all-night 40th birthday celebration.)

“It’s been brought into the light because, over time, its historical significance has grown,” museum conservator Malcolm Collum says.

When Paramount donated the ship to the Smithsonian in 1974, “Star Trek” was just a single short-lived TV series. As the franchise expanded, the Enterprise model fell into disrepair. Sagging nacelles (the ship’s torpedo-shaped engine housings) and flaking paint spurred Collum to take the ship out of the gift shop and into the conservation lab in 2014.

“This is a 50-year-old model and it was starting to show structural failures,” he says. “It made me really nervous. It could have catastrophically fallen apart.”

Collum and his team have restored the ship to what it looked like in 1967 during the filming of the “Trouble with Tribbles” episode, which is when the last-known modification of the ship took place.

Here’s what’s new:

A green-gray paint job. Using the original paint on the top of the saucer as a reference, conservators returned the ship to its proper color by removing paint applied during previous restorations and adding new paint where needed. “People are going to say it looks too green now, but it looked more gray on TV because of the powerful incandescent studio lights,” Collum says.

Space tarnish. Artists from visual-effects studio Industrial Light and Magic applied bronze-colored streaks and specks, lost during past restorations, to the exterior. “It looks like the ship was speeding through space and ran through a cloud of something that splattered across its hull,” Collum says.

Old-school decals. With historic photos as a reference, ILM artists added lettering to the sides of the starship using the waterslide method (the same technology that underlies temporary tattoos) used by the original model makers.

A more authentic deflector dish. Before coming to the Smithsonian, the Enterprise lost its deflector dish — the saucer at the front that projects a force field to protect the ship from space debris. During an earlier restoration, “the museum made a not-very-accurate replacement — we referred to it as the salad bowl,” Collum says. The new dish is a perfect replica, re-created using the original specs.

Lights that won’t cause fires. In addition to blinking lights throughout the ship, the Enterprise’s nacelles appeared to have spinning lights inside, an effect created with motors, mirrors and Christmas lights. The old incandescent bulbs ran hot and actually scorched the inside of the wooden model, which is why they were removed long ago, Collum says. The restored version uses LED lights to replicate the original effects. “When you turn on the lights, it just brings the ship to life,” Collum says. “It’s an incredible transformation.”

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