Following the free-flight tests, "Enterprise" was prepared for ferry flight tests, which were intended to ensure that the SCA/orbiter configuration was viable for flights of the duration between landing and launch sites. Following the end of the flight test program, "Enterprise" was taken for testing with the external tank and SRBs in full-up launch configuration, to test both the structural responses of the "stack" itself and the launch procedures prior to the entry into service and first launch of the first operational orbiter. These tests first saw "Enterprise" taken to the Dynamic Structural Test Facility, located at the Marshall Space Flight Center in Huntsville, Alabama, where the complete stack was subjected to vertical ground vibration tests, assessing the structural responses to a number of scenarios. Then, the orbiter was flown to the Kennedy Space Center in Florida, to test the procedures of assembling the stack in the Vertical Assembly Building, transporting it from the VAB to the launch pad, and to fit check the facilities and procedures at LC-39 to be used in launching the Shuttle.