Space Shuttle Enterprise

https://en.wikipedia.org/wiki/Space_Shuttle_Enterprise

Space Shuttle Enterprise was the first orbiter of the Space Shuttle system. Rolled out on September 17, 1976, it was built for NASA as part of the Space Shuttle program to perform atmospheric test flights after being launched from a modified Boeing 747.

It was constructed without engines or a functional heat shield. As a result, it was not capable of spaceflight.