Original sentence: The main difference is that the four propulsion rockets were not located in the, but in a boost skirt located at the bottom of the test vehicle
Edited sentence: The main difference is that the four propulsion rockets were not located in the forward fairing, but in a boost skirt located at the bottom of the test vehicle.The propulsion thrust was not balanced between the rockets by a manifold system, contrary to what is foreseen with the actual system.The rockets in the fairing were represented by geometric dummies