On March 28, 1963 NASA launched the first stage booster of its new Saturn 1 rocket on a fourth and final test flight. [‘On This Day in Space’ Video Series on Space.com]( br This uncrewed suborbital flight helped pave the way for astronauts to launch to the moon. After this initial test phase, NASA started launching test flights with a live second stage and boilerplate versions of the Apollo CommandService Module. This test flight, designated SA-4, carried a dummy second stage to test the aerodynamics of the real second stage. Another thing NASA tested during this flight was a new system to deal with engine failure. One of the eight engines was programmed to shut off mid-flight. Fuel from the "failed" engine was then re-routed to the other engines so the rocket could keep going.