This rocket propulsion test complex was created to flight-certify all first and second stages of the Apollo Saturn V rocket. The first test-firing occurred on April 23, 1966. Subsequent to the Apollo Program, these test stands were modified to support the testing requirements of the Space Shuttle Main Engine. Every astronaut who traveled to the moon aboard Saturn V rockets and into space aboard the Space Shuttle did so on rocket stages and engines that were first proven flight-worthy on these test stands.