Before the space shuttle traveled in orbit around the planet Earth, the very first space shuttle made test flights with the help of an airliner.
Before the space shuttle, all manned spacecraft were single-use and splashed down in the ocean. The new Space Transportation System would have a re-usable orbiter, and would land like a glider on a runway after returning from space.
The Approach and Landing program used the orbiter Enterprise, named for the popular Star Trek science fiction series, with the help of a modified Boeing 747. The Enterprise rode on the back of the aircraft.
The Enterprise first got off the ground with the first of what were called captive-inert tests on February 18th, 1977. There was no crew on board during this opening test, which helped to ensure the safety and reliability of carrying the orbiter into the sky.
During later tests, there was a crew of two inside the orbiter and actual landings were performed. There were a total of five captive-inert flights, three more captive flight with the orbiter crewed and active, and five tests where landings were performed.
The tests were successful. The Enterprise never went into space, but the testing done in the program by the craft helped pave the way for the 1981 debut of the Space Shuttle, with the launch of STS-1 and the orbiter Columbia.
However, that would not be the end of the Enterprise. In 2012, after the end of the Space Shuttle Program, the Enterprise flew over Washington D.C. And New York City, once again on the back of a jet. It is now on display at the Intrepid Sea, Air & Space Museum. Although it sustained damage from Hurricane Sandy, the Enterprise was fully repaired and remains on display for visitors to see.