39 years ago today we got our first look at Space Shuttle Enterprise.
The Space Shuttle Enterprise, officially called the NASA Orbiter Vehicle Designation or OV-101, was the first Space Shuttle. It was built for NASA as part of the Space Shuttle program to perform test flights in the atmosphere, aided by a modified Boeing 747.
It was constructed without engines or a functional heat shield. The Enterprise was not capable of spaceflight. It was unveiled on September 17, 1976.
After the Space Shuttle Challenger accident, NASA looked into retrofitting the Enterprise to become the fourth operational shuttle before deciding on building a new shuttle, which was later named Endeavour.