(covers information from several alternate timelines)
|Space Shuttle Enterprise on Earth.|
|Owner:||United States of America|
|Status:||Active (21st century)|
|Archer's drawing of Orbiter Vehicle 101|
|Pre-warp ships Enterprise|
|Sail: HMS Enterprize • Enterprise • USS Enterprise|
|Powered: USS Enterprise CV-6 • USS Enterprise CVN-65|
Enterprise was a prototype/test vehicle for Earth's first reusable spacecraft. She was used primarily to verify the performance of the Space Shuttle Orbiter design during final approach and landing and never flew in space. She was displayed in the Steven F. Udvar-Hazy Center of the Smithsonian Institution's National Air and Space Museum from December 2003 until April 2012, and now makes its home at the Intrepid Sea, Air and Space Museum in New York City; Leonard Nimoy attended and spoke at the arrival ceremony.
The first space shuttle was originally supposed to be named Constitution, in honor of the United States' bicentennial celebrations in 1976. However, a massive fan letter campaign organized by Bjo Trimble produced over 200,000 letters asking President Gerald Ford to name the shuttle Enterprise after the Star Trek starship (which, ironically, is Constitution-class) instead.
In the real world, Enterprise (OV-101) was not built to be spaceworthy, and was meant only for atmospheric tests, although NASA intended to upgrade the vehicle for space flight after the test program ended. However, changes to the final design and advances in materials technology in the interim made this too costly; an existing structural test article was used instead to build the shuttle Challenger (OV-099). Enterprise was again considered for modification after Challenger was lost, but it was cheaper and easier to build Endeavour (OV-105) out of structural spares. (citation needed • edit)
The model of the Enterprise docked with the International Space Station seen in Sisko's office on Star Trek: Deep Space Nine was given to the series as a gift by Majel Barrett. (Star Trek Encyclopedia)
Footage of the shuttle Enterprise included in the montage of historic images shown during the opening credits for Star Trek: Enterprise is actually one of the later shuttles with the name Enterprise digitally inserted. The footage shows the orbiter's name on the forward fuselage under the cockpit windows, where the operational shuttles had their names painted; Enterprise had her name painted on the payload bay doors just above the hinge and behind the crew module, where it remains to this day.
The Artisan prop and model shop of Quantum Mechanix, QMx FX Cinema Arts, was asked to illustrate the history of space flight with models for the film. They constructed fourteen models in total. On their website, along with a picture of the model of the Enterprise, there was this caption, "It's all well and good to send people up in rockets for brief periods, but to make human habitation of space a reality, we needed a way to ferry crew and supplies to permanent orbital stations. The U.S. Space Shuttle supplied the solution to that challenge for more than two decades. It also has the distinction of having the first spaceship named Enterprise, which ironically never actually flew in space." 
The novel A Flag Full of Stars states that she instead was named for the World War Two aircraft carrier because the brother of one of the engineers who worked on her died serving aboard said ship, and that she was the last surviving space shuttle. She was refitted with impulse engines so she could participate in a parade of antique spacecraft celebrating the 300th anniversary of Apollo 11.