James Burke discusses the use of hydrogen and oxygen as rocket fuel, saying, "If you release those two gases into a confined space, with a hole at the other end of it, and mix them as you do so, and then set light to them, you get that." He then points to a rocket launching. In fact, the rocket being launched (carrying the Voyager 2 space probe) did not use hydrogen and oxygen as fuel at liftoff. It was a Titan IIIE rocket, fueled by nitrogen tetroxide and Aerozine-50, assisted by two solid rocket boosters. The third-stage Centaur booster would be powered by hydrogen and oxygen later in the flight.