The Shuttle Avionics Integration Laboratory (SAIL) was a facility at Lyndon B. Johnson Space Center in Houston, Texas. It was the only facility in the Space Shuttle Program where actual orbiter hardware and flight software can be integrated and tested in a simulated flight environment. It supported the entire Space Shuttle program to perform integrated verification tests. It also contained Firing Room Launch Equipment identical to that used at KSC. Thus complete ground verifications as well as countdown and abort operations could be tested and simulated.