 In 2002 the upgraded Vulcain 2 with 20% more thrust first flew on flight 517, although a problem with the engine turned the flight into a failure.The cause was due to flight loads being much higher than expected, as the inquiry board concluded.Subsequently, the nozzle was redesigned to include mechanical reinforcement of the structure and improvement of the thermal situation of the tube wall through enhancing hydrogen coolant flow as well as applying a thermal barrier coating to the flame-facing side of the coolant tubes.