Saturn I SA-4

SA -4 was the fourth flight test of the first stage of a Saturn I with dummies of the second and third stage.


Due to the size and power of the Saturn rocket family NASA decided to conduct a test flight for each component of the rocket. During this flight, only the first stage was active, the second and third stages were filled with water to simulate the starting weight. Should be tested, to the conduct of the rocket with an engine failure, on the other hand, the aerodynamic characteristics of the second stage. For an engine was set so that it turns off after 100 seconds of flight and the second stage was provided with valves, screws and the like. Furthermore, the braking rockets of stage separation should be re-ignited.


The missile was delivered on 2 February 1963 by sea and then within 54 days - until then the shortest time in the program - mounted.

History of the flight

The countdown should be the longest so far in the Saturn program with a total of 120 minutes interruptions. The rocket finally lifted off at 20:11:55 UTC from March 28, 1963. The flight was scheduled to shut down an engine after 100 seconds properly. Instant on-board computer automatically distributed the fuel supply new, to ensure a safe flight with only seven of the eight engines and to reach the target height. After burnout, the braking rockets were fired. The rocket crashed after this maneuver in the Atlantic.

The test was a complete success. It has been proved that the onboard computer can compensate for the failure of one engine - this should be important in Apollo 6 and Apollo 13. There were no problems with the aerodynamic second stage.

With the next flight SA -5 now the stage separation and ignition of the second stage should be tested.