Space Center Houston is removing its nearly 25-year-old mock space shuttle Adventure to make way for a new exhibit about the future of Mars exploration.

HOUSTON — For almost 25 years, visitors entering Space Center Houston have been greeted by the sight of a space shuttle emerging from between two doors.

That orbiter's mission is now coming to an end. The "Adventure" is being removed. (See photos of Space Shuttle Adventure at Space Center Houston.)

The shuttle mockup, or at least the orbiter's nose-section protruding from a façade designed to look like NASA's Vehicle Assembly Building in Florida, gave the public in Texas a chance to see the sheer size of the spacecraft's crew cabin, inside and out. But, with the real orbiters retired and with the recent addition to Space Center Houston of a full-length replica orbiter, the Adventure is giving way to the future of space exploration. [10 Amazing Space Shuttle Photos]

"There are a lot of really good things going on and we want to do so much, but we have filled the building and we are out of space. We need more space," said Paul Spana, the exhibits manager at Space Center Houston, which serves as the visitor center for NASA's Johnson Space Center. "One of the stories that we want to talk about is the future."

A new exhibit devoted to NASA's plans for a "Journey to Mars" is set for the space where Adventure is displayed.

"Mars is a good thing to talk about," said Spana. "If we don't go to Mars in the next 20 to 30 years, we're eventually going to go to Mars at some point. We want to talk about that, even if it is a long-range goal."

But that means Adventure has to leave.

"Though most people here who grew up with the shuttle are sad to see it go away — because it has been here for such a long time — by taking Adventure down, it will give us more space to talk about something new, which is the future and, in this case, Mars," Spana said.

Beginning on Tuesday (Sept. 6), the work will begin to disassemble Adventure and remove its walkthrough middeck and flight deck displays.

"We are going to take it down, for the most part, as it came in," described Spana, recalling the Adventure's delivery and installation in 1992. "We're going to break it down into smaller pieces. It was pre-built in Florida and shipped here in big pieces, ready to be assembled like a giant 3D puzzle."

Space Center Houston’s mock space shuttle Adventure features a walkthrough interior crew cabin, including the forward flight deck pictured here, reproducing the commander and pilot stations. (Image credit: collectSPACE.com)

Adventure, however, may leave in more parts than it originally came.

"One disadvantage we have now is that some of the larger pieces won't be able to get out the door because Adventure came in before the doors were installed. So, we may have to cut it up into smaller pieces to get it out," said Spana.

At least one other museum has expressed interest in relocating Adventure, though it may depend on its condition after disassembly. Spana hopes that the shuttle can be preserved.

At the least, some of Adventure's parts will move into Independence, the full-scale orbiter mockup displayed atop NASA 905, NASA's historic Shuttle Carrier Aircraft, outside of Space Center Houston. The $12 million Independence Plaza opened in January.

"There are a few areas inside Independence that I wish had more detail," Spana said. "A good example of that is the [food] galley."

"The galley that is in Independence now has really no detail to it at all. The galley that is inside Adventure is pretty nice. I just did not want to take it out of there. But with Adventure coming down, this will give us the opportunity to take the galley out and move it outside," he explained.

A temporary barrier will be going up so that Adventure can be removed while the center remains open to the public. The work is expected to take about a week.

"We want to get it out as soon as possible because we are going to need a lot of time to prepare the space for our new exhibit," said Spana.

View the mock space shuttle Adventure as it looked just before its removal from Space Center Houston at collectSPACE.com.

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