Although the airframe and flight control elements are like those of the Shuttles flown in space, this vehicle has no propulsion system and only simulated thermal tiles because these features were not needed for atmospheric and ground tests.
Space Shuttle Enterprise
The first Space Shuttle orbiter, Enterprise, is a full-scale test vehicle used for flights in the atmosphere and tests on the ground; it was not equipped for spaceflight. Its main role was to check the Shuttle's flight characteristics and performance. NASA conducted approach and landing tests from February through November 1977 at the Dryden Flight Center.